SOFIA Coppola and boyfriend Thomas Mars are going strong. The “Lost in Translation” director and the lead singer of French rock band Phoenix, who have a 3-year-old daughter together, hung out all night at the after-party for the band’s Central Park show at new pingpong club SPiN. “They were holding hands the whole time,” says an onlooker. Also watching the tournament at the club on Friday were DJ Paul Sevigny designer/actor Waris Ahluwalia and SPiN co-owner Susan Sarandon.