Oh thank god... same here too, Jazz 15mnths does not know what has hit her since Bailey arrived in August.
Shame is Bailey seems to really love Jazz and always (when not play fighting) wants to cuddle up next to her but Jazz has only allowed this a couple of times, mostly she will just move if Bailey tries to lie where she is.
A lot of the time the fighting is playful and Jazz will often instigate it too so can't just blame Bailey but she is relentless and even when Jazz has "told her off" she still comes back for more.
I keep my eye on them and while tails are wagging I am quite sure it is playful but Bailey is also very vocal so it sometimes sounds like a full on pit bull fighting ring

Jazz has yelped a couple of times when the ear biting has been a bit too hard but to her credit has not retaliated and Bailey has been given time out in these instances.
Jazz has however over the last couple of weeks become what I would say is less tolerant and will give a low warning growl to Bailey before she can try to lie with her.
The rest of the time they are fab together, on walks Jazz loves to be chased and Bailey is happy to oblige, Jazz's recall is much better since Bailey has been around and they will happily drink from the same bowl at the same time and share all their chews, toys etc with no problems. Feeding time is great they just have to lick each others bowls when they have finished

Bailey is always crated when I have to go out and at night so they are never alone together but I am hopeful one day as she gets older I will be able to leave them together with confidence.