Just three months after opening in the sizable Lafayette Square space that previously held Tripel, Balentine's(1801 Park Avenue, 314-833-4339) is already shifting gears.In recent weeks, owner Pierre Balentine tells the RFT, he's begun a rebrand to focus on sports and games. Instead of an upscale lounge, he's brought in a pool table, a jukebox and video games to fill the 5,400-square-foot restaurant and bar.…