Typically a restaurant sets the price of a single glass of wine to recover their purchase cost on the entire bottle.
[3] The industry average price markup for bottles of wine ranges from 2.5–3 times the establishment's wholesale cost.
Wine lists have traditionally been implemented in paper, usually protected by some kind of cover like the ones seen on the normal restaurant menus.
This kind of implementation usually leads to some entries being unavailable due to stock issues, since business owners are unlikely to change the wine list daily.
Recently, a growing trend in the restaurant industry has been to adopt digital wine lists, presenting it to patrons on tablets and similar devices.