Celts captain Paul Pierce and wife Julie dined with friends — and drank Dom Perignon — at Yellowtail Japanese Restaurant and Lounge in Vegas over the weekend. . . . Meanwhile, Pierce’s teammate Jeff Green gorged on clam chowder and a crabcake sandwich at Legal Sea Foods in Park Square Sunday night. . . . Larry David drew a few quizzical looks from passers-by as he wandered around the Back Bay Monday.