The cruise lines are getting stricter from what I hear. Had friends have their wine/Vodka confiscated at check in, and returned at disembarkation. Especially after 9/11 ALL bags are x-rayed (as they should be) and the bottles show up. You can try, but don't be surprised if it's not allowed. It may depend on the policy of each cruise line.
I'm also planning to go on the Atlantis cruise. A tip i can pass along is go to the store and buy a 1 Liter bottled water. Dump out the water, replace with vodka and pack in your checked bags!! Now you have something that looks like water but isnt and its less likely to break than the glass vodka bottle
From what I have gathered from reading many of the message boards on this subject, you should do OK if you pack liquor in your checked luggage. This particular ship has evidently had a "wink and a nod" attitude so far. I don't know if, being an Atlantis charter, they will be even more strict, but this is the route I'm taking.