Just a side note, but the amount equal to one individual's "personal consumption" may be vastly different than that of another person.

That being said, and this is not legal advice, only a description of personal experience, I think the customs forms use to require disclosure of alcohol, but as someone else mentioned, I don't think they do now. When we traveled to Italy about five years ago, we brought back 6 bottles of wine, expecting to pay duty on 4 of them, because, at the time, a person could bring back somewhat less than 2 bottles duty free. The customs agent in Atlanta asked us about the wine, and then passed us right on through with no duty.
This last February, we brought back four bottles of vanilla rum in our checked luggage (the most weight we could add to our bags without going over the SBC weight limit, even after dumping all our sunscreen and toiletries), and although my husband filled out the customs form, I think he told me there was no longer a place for declaring alcohol. If asked, we would have declared it, however, four international flights landed about the same time in Charlotte, and customs was so swamped, I don't think they had time to ask about anything but the basics.
For future reference, a wine purveyor near us sells what amounts to bubble wrap bags that completely seal up in case of a cork malfunction for the purpose of bringing back bottles in luggage. You might inquire at a wine store near where you live prior to your next trip. Since we brought ours from home, I don't know if any place on the island has such an item or not.