I've heard that some cruise lines offer wine packages, but this is the first I've heard of alcohol packages. Some cruise lines I know also offer fountain soda packages.
Until this post, I haven't heard of cruise lines doing alcohol packages. It should be noted though, on some cruise lines, if a bartender determines that a passenger has had too much, they can refuse to serve that person a drink.
2007 - Majesty of the Seas
2009 - Enchantment of the Seas
2010 - Freedom of the Seas