I don't see a problem with it as long as its monitored and in moderation.
I know plenty of teens that drink...most of them don't do it in moderation though.
I think it's fine as long as someone takes everyones keys as they walk in and doesn't give them back until the morning. I've lost a friend in a drunk driving accident thats the only reason I say take the keys.
Now if you're drinking in your house and don't go anywhere then I say drink what you want as long as you know how it will effect you.