The US Virgin Islands (as the name implies) is part of the US and has been since we bought the Island from Denmark in 1917.
The Jones Act was passed in 1920.
Something few US mariners know is that the Jones Act has always contained a carve out for the US Virgin Islands. Basically, the Jones Act does not apply to the US Virgin Islands.
Foreign flag, foreign owned, foreign built, and foreign crewed vessels may carry cargo and passengers within, and/or to and from the Virgin Islands to the US.