Artists Against Abuse Benefit
         By: Isa GoldbergOskana Grigorieva I saw Elvis. Others with peace signs, and still others wearing tie-dye were dancing to The Fabulous Sixties Rock Show, tossing rings at bottles of wine - hoping to win one, and rubbing shoulders around the bar. The Retreat's 18th annual Artist Against Abuse benefit, an evening painted fabulously psychedelic, drew a crowd of apparently ageing hippi…