My iPhone 6 is 9.1, about to download Public Beta 2. The 6S is 9.0.1.
I think I also have an encrypted backup of the iPhone 6. How do I see that when I try to restore it to the 6S? I do want my healthkit, etc. info on the new phone.
Once you update your 6S to 9.1, you should be able to restore your 6's backup to it. If it's encrypted there's nothing special you need to do, it'll just prompt for the password you encrypted it with when you pick it to restore.