I've checked cases of wine several times on US flights. First, if anything breaks, US will NOT reimburse your for the breakage. Alcohol is specifically excluded from the damage policy. Also, when you check in (especially if you are coming from a wine region) the ticket counter people will see the box and ask what is in it. When you tell them wine, they will likely make you sign a release.

FWIW, I usually check the wine in a cardboard wine shipper box with a Styrofoam wine bottle insert. I have never had a problem, nor has any bottle ever broken.