There has been disagreement about the location and title of this image by library cataloguers and picture historians for some time. Copies are held by the picture collections of the National Library of Australia (NLA), State Library of NSW (SLNSW), Royal Historical Society of Victoria (RHSV) and Australian Performing Arts Collection, Arts Centre Melbourne. All except the RHSV image (which is a hand-tinted glass lantern slide) describe the image as being located in the bar at the Theatre Royal, Melbourne. It shows a brightly lit mirrored saloon-bar with the focus on actor and entrepreneur George Coppin (in dark coat and top-hat). This copy, a ‘Paris Panel’, is held by the State Library of NSW and until recently, was catalogued as ‘The bar of the Theatre Royal, Melbourne, ca.1865 / photographer Talma’. In January 2020, the catalogue record was amended to read the ‘Crystal Bar, Cremorne Gardens, Richmond, Victoria, ca.1860’.
Mitchell Library, State Library of NSW, SPF/2280, https://search.sl.nsw.gov.au/permalink/f/1cvjue2/ADLIB110357814
Another copy (without the hand printed names) is held at the National Library of Australia with the title ‘George Coppin (in tall hat) in the Marble Bar in the Theatre Royal, Melbourne, 1861 [picture] / Talma’.
Both are copies by Talma of an as yet unfound original likely to have been photographed in the late 1850s. Both copies appear to be identical except the SLNSW copy dated 1865 has a mark near Coppin’s eye while the NLA copy dated 1861 is clear. It is likely that Miss Coppin owned them both, giving them to biographer Alec Bagot to use in his book on her father. 
Helpfully, someone has identified a few of the eleven people pictured. (Left to right: third and fourth from left W.J. Wilson and W. Pitt, both in the employ of Coppin as scenic artists at his Cremorne Gardens in the late 1850s and early 1860s (both for the gardens’ Pantheon Theatre, and modelled panorama and fireworks shows). More important in trying to locate and date the photo, one of the men behind the bar, sixth from left (in a dark shirt) is named as ‘Peachman’. Henry Peachman is listed as manager of the ‘Crystal Bar’ in advertisements for the shows at Cremorne Gardens in 1858 and 1859.  Eighth from left, George Coppin (proprietor of Cremorne Gardens), tenth from left, medical entrepreneur and showman, L.L. Smith. Eleventh from left Tupper, a barman.
However, I believe that the photograph was taken at the ‘Crystal Bar’ at Coppin’s Cremorne Gardens in the late 1850s, most likely to commemorate the opening of the Crystal Bar in November 1858 as all the people in the image have direct association with that event. As noted in an advertisement in The Argus of 15 November 1858:
OPEN FOR THE SEASON
ON MONDAY EVENING NOVEMBER 15
The Panoramic Picture
By Messrs. Wm. Pitt, W. J. Wilson, Herr Habbe,
Is taken from authenticated views of
FALL OF DELHI
The Crystal Bar is unequalled in the World;
Conducted by Mr. Peachman …
The 1865 date on the SLNSW photograph is clearly incorrect as in 1865 Coppin was in the USA with the Keans. (See Simon Plant’s Show Time: George Coppin turns 200, https://theatreheritage.org.au/on-stage-magazine/general-articles/item/574-show-time-george-coppin-turns-200)
During the gold-rushes of the 1850s there was a demand for the entertainments of ‘Home’ such as the ‘pleasure gardens’ of London, including Surrey and Vauxhall Gardens. Cremorne Gardens, Richmond, Victoria was originated by caterer James Ellis, the insolvent founder of the London Cremorne Gardens at Chelsea. Unfortunately, after much expenditure and only three years, Ellis again became a bankrupt and George Coppin actor-manager and G.V. Brooke tragedian purchased the property.
During its ten-year life (usually open each summer from November to April), Cremorne Gardens, an early kind of amusement park, featured an out-door dancing Rotunda, firework shows over the lake and panoramic models (constructed of timber, plaster and painted canvas) usually about 122 metres wide by 15 metres high (like a film set). These changed every summer e.g. The lakeside siege of Sebastopol might become the Fall of Delhi or Vesuvius and Naples!) There was also the Pantheon Theatre showing dramas and pantomimes with audiences encouraged to view the fireworks display from the theatre’s outside balcony at 9.30.p.m. There was also a circus showing equestrian ‘hippo dramas’ as well as tight-rope walking on display across the lake. A menagerie held camels, lions and an elephant. Throughout the gardens plaster copies of famous statues perhaps ‘improved’ the visitor’s mind and an on-site gas-works helped illuminate the pathways. Eventually a railway line to the pleasure gardens was added to the little river steamers known as gondolas. 
Theatre Royal, showing the Royal Hotel (left) and Café de Paris (right). Photograph printed in 1933 by the Sears’ Studio from original negatives taken by them in 1861.
State Library of Victoria, H20742, https://handle.slv.vic.gov.au/10381/109898
Alcohol and popular entertainments often go together. In the nineteenth century—male theatre goers had access to several bars within the theatre and adjacent hotels. For example the Theatre Royal in Bourke Street Melbourne, as described in the 1861 pamphlet, ‘Opinions of the press on Messrs. Spiers & Pond's management of the Café de Paris’, had the Royal Hotel and several ‘American bars’.  Could the photo have been taken at the Theatre Royal?
After conferring with Melbourne image and architectural historians Terry Sawyer, Peter Johnson, Miles Lewis, Rohan Storey and Allister Hardiman, I contend that the photo has been wrongly titled—there was no ‘Marble Bar’ among the various bars at the Melbourne Theatre Royal!  Therefore it should be located at Coppin’s Cremorne Gardens, Richmond, rather than in the Bourke Street theatre.
We can get an idea of where the Crystal might have been with the help of a block plan of Cremorne Gardens prepared for its subsequent use as a psychiatric asylum.
Architectural historian Peter Johnson concluded that the photograph in question must have been taken at the Crystal Bar in the refreshment rooms (otherwise known as the Hotel) near the Pantheon Theatre for the following reasons:
Note the curved corrugated iron ceiling (u/s of the roof) and the metal rods bracing the roof structure in the image. This would indicate a metal portable building or similar structure. Highly unlikely to be part of the Theatre Royal building in Bourke Street notice the windows reflected in the bar mirrors, indicating a wall of windows opposite the bar along the long axis of the space and also at the end of the room. In addition, the dappled light in those windows would indicate that there was planting outside. In the attached illustrations of the Cremorne Gardens, the refreshment building opposite the Pantheon Theatre has a curved roof and conforms perfectly with the characteristics described above.
Detail of Calvert’s engraving of Cremorne Gardens, with annotation by Peter Johnson, showing Refreshment Rooms [aka Hotel].
State Library of Victoria, MP20/12/62/8, https://handle.slv.vic.gov.au/10381/246532
Peter Johnson’s further hypothesis based on the architects’ plan and clipping from the Talma photograph:
A verandah, probably runs along the back wall of the bar, across a sunlit yard to a building opposite with a panelled door. The blue dotted line is the view that I am talking about leading to the cook’s bedroom door. The bathroom in the way is a later fill-in in the bar's verandah.
Image researcher and architectural illustrator Allister Hardiman has, together with an isometric study of the Theatre Royal, made a metric analysis of the Talma photograph and found that there would have been no room in the Theatre Royal building for the Bar. (Click here to download)
The mistake was probably made by Coppin’s daughter Lucy (1873-1960) when she appeared in the documentary Theatre in Australia and identified the photograph as showing her father in the ‘Marble Bar’.  However, it is clear that Miss Coppin, confused the Crystal Bar, opened c.1858, with the Marble Bar in Tattersall’s Hotel in George Street Sydney, and from a very different era, opened in 1892.
Several factors might have led to this confusion: a) Miss Coppin was born ten years after Cremorne Gardens had closed, b) so she had to rely on family hearsay, possibly from her father and brothers mentioning a Marble Bar out of context—as a lady she would not have been admitted to any bar (she was a lively 78 years old when she appeared in the film with the image in question in her hand). 
Of her statement that it was the ‘Marble Bar’ with her father at the Bar in his Top Hat, exhaustive research in Melbourne newspapers for mention of a marble bar in the Theatre Royal proved unsuccessful. Indeed, the only reference to marble in relation to the Theatre Royal building was to tables in Spiers and Pond’s Café de Paris coffee room near the Dress Circle entrance of the theatre. 
There is evidence that the abundance of plate-glass and crystal in the photo was from Coppin’s rushed visit to London in 1857 where he said that he had purchased 20 tons of glass for his Cremorne  and boasted how he had imported plate glass mirrors and crystal chandeliers from Defries of London allowing them to advertise their presence in his ‘Cremorne Melbourne, Australia’ venture.
Amid the nineteenth century puffery and publicity of an Argus ‘penny a line’ review we have perhaps the best description of Coppin’s crystal bar:
We are almost sorry to be compelled to speak of the bar in terms of higher praise than those we have used regarding any other part of the gardens, but certes it is one of the handsomest places of the kind we have ever witnessed. An air of coolness and increased spaciousness has been given it by the erection of a wall of plate-glass in the rear of the counter. At the top of the mirrors at the back of pendant crystals are the jets of light which illuminate the place. Statues and flowers vases and pictures, are deposited wherever there is a chance of heightening the general effect. Altogether, as an exhibition of taste devoted to a special purpose, we imagine the bar may challenge competition with anything of the kind in either hemisphere. In our own country this style of drinking is rarely attempted. It is in America where they are found in the greatest perfection, and we therefore must leave it to our trans-Atlantic brethren to decide upon the comparative merits of this Bacchanalian resort. 
As if to assure later enquirers of the location of the Coppin’s Crystal Bar the local newspaper, Richmond Australian, 30 April 1864 (a year after the Gardens closed) published an article describing the state of the Gardens since becoming a private Lunatic Asylum. Among the nostalgic memories is the sentence:
The main building is that formerly known as the crystal bar, and this is divided into six sleeping compartments, and a large dining room, for gentlemen.
Many years later a Marble Bar did open, but not in Melbourne. Rather than a mid-Victorian saloon, with glittering mirrors and crystal chandeliers of an amusement park it was the Marble Bar in George Adams’ Tattersalls Hotel Pitt Street Sydney c.1892. A High Victorian ‘other world’ complete with Julian Ashton nudes. (The bar was dismantled in the late 1960s when the hotel was demolished and reassembled in 1973 in the new Hilton Hotel.)
1. Alec Bagot, Coppin the Great, Melbourne, MUP, 1965
2. The Argus (Melbourne), 13 November 1858
3. Mimi Colligan, ‘Cremorne Gardens, Richmond and the modelled Panoramas 1853-1863’, VHJ, vol. 66, No. 2 October 1995
4. Opinions of the press on Messrs. Spiers & Pond’s management of the Café de Paris, Melbourne: and of many of the principal enterprises with which they have been connected’, p. 5.
5. It is likely the photographs of the bar itself were part of Miss Coppin’s own collection.
6. Doc K. Sternberg, Theatre in Australia, Department for the Interior, National Film Board, 1952, https://www.youtube.com/watch?v=QONAuO8oBhM
7. She went on to assist Alec Bagot in the publication of his biography of her father, Coppin the Great (1965) giving him access to Coppin memorabilia in her will and sometimes misleading him with incorrect memories.
8. Opinions of the Press, on Messrs Spiers and Pond’s management of the Café de Paris, Melbourne 1861, p. 6
9. The Era (London), 27 September 1857
10. The Argus (Melbourne), 16 November 1858