my 1yr old staff bitch keeps biting my mums 3yr old male staff, usually around the nose, cheek and throat area. i've been told that they are just bonding but am worried as it can look quite aggressive, is this normal?

If by biting you mean mouthing with a lot of noise (and slavers) but no blood then yes it's perfectly normal play behaviour. My lot can sound quite ferocious at times, with snarling, growling, yowling and the odd high pitched squeal but they never actually mark each other :-)

My Schnauzer does this to my younger TT all the time and sometimes it looks quite scary but it's all part of playing. As long as things don't get out of hand. i'm sure the older dog will put your one year old in his place if he hurts him.
if i think things are getting a little to heated then just distract with a treat to calm things down and then they forget what they were doing.
Shouldn't worry about this i'm sure you'd notice if things change and start going to far.

As already indicated, quite normal, the more alpha females are very prone to doing this and will actually clamp their teeth around the nose  of the resident male with a lot of noise but no teeth marks or blood, the male will then submissively lick the mouth of the female, so you do not need to interfere the bitch in general takes over and she is now of an age to show her authority, she won't hurt him, if she does he is not being complient in which case problems may occur, but I've very rarely come across a male who will not allow a bitch her role. So don't worry, it's just the way dogs communicate. :-) No blood, no worry!!!!

Very normal staffie way of playing! I've got brother & sister here both staff x's and she will pin him to the floor and well look like shes riping his throat out! I will only have a moan at them when the noise levels gets extreme- it sounds pretty mental! I let them have there fun but when one you can see is rather tired and looks like its had enough of rough play time- call an end to it, get her to lie down have time out- like having kids really lol most probably the one that was looking hen pecked will go over and start up the play fight again! :-)

Staffords can be very vocal when they play but they still need supervising. You still need to step in if you think its getting out of hand as a fight can break out in a split second between any breeds if they get too over excited

Yes normal, but i find bitches can be a bit more so then usual and the 3yr old boy will put up with her even if it hurts, so you need to step in from time to time to calm her down. She might do it to a less tolerant dog one day. Also staffie tend to play staffie like with other staffies only and play less rough with other dogs, so you want to make sure that is the case.

My boy has a young staffie bitch he plays with and at times he looks like he is a contortionist! She gets old of the skin on his throat and pulls from underneath him forcing his head through under his front legs! He never gets that bad with any other dog and if I don't watch sometimes he gets tired of that and tries to stop she gets quite annoyed with him then, so it's best to stop before then as game excitement can turn into an argument very quickly...