I'm sorry, I'm not sure what you mean by "AirPlay." I was synced to the Bose Soundlink II via Bluetooth. I am still synced to the Bose with my Samsung 4G phone (for Pandora), and that works fine. I didn't do anything different with the iPod, it just stopped syncing. I will probably end up going into either the Apple or Bose store at the Mall. Just thought I would take a chance to avoid the trip.
For Bluetooth it is called pairing, not syncing.
Try resetting the Bose device again and als on the iPod go to Settings>General>Reset>Reset Network Settings. You will have to re-pair to the Bose device and reenter wifi passwords.