LAST year, Bonnie Gokson invited guests of the Community Chest to a $5,000-a-head dinner-and-casino bash on board the Queen Elizabeth II . . . this time the superliner will be more accessible to music fans in Hongkong when it docks in mid-March. The Ladies Committee of the Hongkong Philharmonic Orchestra has commandeered the Cunard Line's flagship for the highlight of its concert series, ''On a Jazz Note'', for the night of March 17. A quintet from the Hongkong Philharmonic will perform under the stars (let's hope it doesn't rain) before guests proceed to a seated full-buffet dinner prepared by the ship's executive chef and music from the New Orleans Jazz Quartet, followed by dancing to the music of the Ashley Staton Band. Co-chairwoman Harriet Tung tells us that proceeds from the night will go straight to the orchestra, and she's taking bookings now. You can advance three rungs on the social ladder by calling her on 721 2030.