I hardly ever drink alcohol when flying, so I don't have the greatest recall on this, but I think there's still champagne in domestic first on some airlines (e.g., I think it's on United). I can't remember seeing champagne in coach. And I wouldn't normally suggest it, as I don't think it's a great deal, but you can buy day passes to some of the airport clubs, for which you'd often have to pay extra for drinks (depends on clubs and type of drink). As you may or may not be aware, the clubs really aren't that nice, but are sometimes better than the alternative.
The main thing I'm writing to suggest though is that if you don't get a good answer here is to check out Flyertalk, where your question may already be answered and, if not, people will absolutely know. You probably need to check the airline specific forums.
http://www.flyertalk.com/forum/