It really wasn't a bonus riding on it, here is what Jim said it was:
"Gentile had to laugh Wednesday. He had nearly been written off as a career minor leaguer back then. He barely made the
Orioles in 1960, and in 1961 he made just $15,000 while piling up all those RBIs.
After that, he negotiated a new deal with Baltimore general manager Lee MacPhail, doubling his salary to $30,000.
"We argued over the contract," Gentile said. "I remember MacPhail, at the time I signed the contract, said that if I had led the league in RBIs, it would have been worth $5,000 more."
Lee's son, Andy McPhail, is now the Orioles GM