Do some bloodline of pitbull have bull mastiff in them?

Yes, some bloodlines of pitbulls have Bull Mastiff in them. The American Pit Bull Terrier is a mix of several breeds, including the Bulldog and the Terrier. The Bull Mastiff is a mix of the Bulldog and the Mastiff. So, it is possible for a pitbull to have some Bull Mastiff blood in them.