Holy shit, first of all how the hell did you manage to hit 210 bench at 115 bodyweight that is seriously impressive as hell! Once you start putting on more size you’ll be putting up some crazy numbers on bench and squat. Anyways if you wanna gain weight and size you just gotta eat more calories day in and day out. I would keep your diet relatively clean though and don’t eat too much sugar cause you really don’t wanna dirty bulk speaking from experience