Antique Tantalus

This looks more like a wall sconce with candle snuffer. I have something like this myself. Probably mid to late 1800's. These were used for lighting, and they were attached to walls and a candle would be placed in them. The snuffer, which is on the top of your bottle was used to of course, put the candle out. there seems to be a key in your item, which tells me that this probably belonged to a wealthy family, and was used as an outdoor porch light. The key would lock everything together, deterring thieves from stealing the precious metal holder. This probably is gold plated judging by the key lock design. Although I can't give you an exact value, I can tell you that mine is wood and iron, no key, and not near as old, and the one I have is worth $1,000-$1,500 at auction.

 What you have here is called a tantalus, (Because it's designed to tantalize), originally it would probably have been used in a relatively large house with servants, and would allow the liquor to be kept on display, while keeping it safe from anyone but it's owner. I have no idea what yours would be worth, but it is a very cool item!