From the USVI, the actual limit is 5 liters of alcohol.

* The duty exemption for travelers returning from the U.S. Virgin Islands is $1,600. You may include 1,000 cigarettes as part of this exemption, but at least 800 of them must have been acquired in the U.S. Virgin Islands (keep your receipt). You may include five liters of alcoholic beverages in your duty-free exemption, but one of them must be a product of the U.S. Virgin Islands, Guam, or American Samoa.

Per the CBP website. link


* U.S. residents 21 years of age and older can return to the mainland with four litres of liquor, duty free. Add a 5th litre duty free if it is a product made in the U.S. Virgin Islands (Captain Morgan and Cruzan Rum)!

St. Croix tourism website. link



The limitations are also based on volume and not the number of bottles.