I was annoyed to learn this AFTER booking Westin St John and clicking through a few links in on the web page
https://www.vistana.com/destinations...transportation
Buried in the link it states:
Marriott Bonvoy™ program may be earned for qualified charges at the resort. As a villa property, we are unable to offer select Marriott Bonvoy™ Member benefits for ownership reservations, including complimentary room upgrades, Suite Night Awards™, priority late check-out, Your24™, and Gold Elite and Platinum Elite welcome gifts.