My male Hob is trying to mate all my females who are neutered, he's bitten them quiet badly around the neck area, where it was actually bleeding, would it be cruel to seperate him from the others for a while, will hes being horny!
Or get him neutered too??

I would seperate him for now & then  get him neutered ! I had the same problem when we put an entire male(who we were looking after until his owner picked him up) in with my neutered males .

Yep, I would separate and neuter or vasectomize. I've only ever kept jills but I was told recently that the hobs come into season as well as the jills, so it could be that he'll calm down when the breeding season ends. If you don't want him neutered you could separate until he calms, I don't think it would be cruel as long as he gets plenty of luvs from you in the meantime, it may even be a relief for him as I imagine he is rather frustrated being in with the girlies and not being able to do his thing.