Arya wasn't Bolton's cupbearer on the show anyway; that's only in the books.
Bolton is one of Robb's lieutenants. He's had a number of small appearances, but like DalekJim
says, the show hasn't made him particularly memorable. He's the one who agreed to release Jaime from Harrenhal in exchange for Jaime telling Tywin that Bolton had nothing to do with his hand being cut off.