I just got off Voyager last week, and here's the "new" policy on alcohol: If you want to bring it onboard with you they will take it at the gangway and give it back to you the last day. If you want to buy it in the liquor store onboard they do the same unless you want to pay an addtional 9 bucks ontop of the price and take it back to your cabin.
That's what we did. We put 2 bottles of wine in suitcase before getting on board. (not in your carry on bc they xray that) You could do the same with other bottles of alcohol for mixed drinks-just pad them well so no breakage happens. We saw people bring on soda in cans with no trouble.