The ENTP I know is definitely a bully. He doesn't think of it that way, but he gives everyone shit about everything, including poking at topics that he knows are sensitive. He thinks it's funny... It's only funny a couple of times, but he does this nonstop. He's also a bit on the manipulative side. He seems like a nice guy, but he's only nice so people owe him a favor.
As a female ISTP, I certainly wasn't the popular kid in the class, but I wasn't bullied a whole lot. I had a couple of friends and I was mostly left alone. So I guess people didn't seek me out for bullying altho when given the chance, kids are mean. *shrug*