The St. Thomas Club, a late, late spot crowning a hill dominating the harbor at the eastern end of Charlotte Amalie, ranks as one of the most unusual, fashionable, and entertaining after-dark meccas in the Virgin Islands, if not the Caribbean. The reception here is totally personal. Host Bob Ellis has left the living room and adjoining terrace as it was when the family was in residence. A vibrant baritone who is not above spoofing his own act, Bob also tickles the ivories a bit, though in this department his partner Dillson Petrie has no peer. Together they spin lambent melodies from 11pm until the wee hours, batting the conversational ball back and forth with patrons gathering around the twin pianos; between numbers they pull up a chair and chat. Although not a penny is spent on promotion, internationally a-la-page pilgrims congregate regularly here. That new fellow at the piano, for instance, might be Leonard Berstein on a businessman's holiday; like many other "names,' he enjoys the open-shirt-and-shorts easy informality of being just one of the gang. An elegant mirror-lined dining salon is part of the plant, and we've had some marvelous meals in it, but always as guests. We can't make a professional check, because the bosses keep such an eagle eye that we haven't been able to sneak in to grab a check. According to what we hear from a lot of satisfied customers, including some mighty-hard-to-please Parisians, the fare is faultless. The ubiquitous Rover Boys from Cornell reported to the Governor that the linen had holes it. "Indeed it does," Bob Ellis replied when queried by Government House on the matter. "That's the way it comes to us-from Madeira." Set aside your prejudices against moonlighting, take an afternoon nap if you must, but don't leave St. Thomas without dropping in on this delightful cabaret. Admission $1, 2-drink minimum; one of our very favorite let's-celebrate spots.