Apple Pay / iPhone 5s
I have an iPhone 5s (latest software) and Apple Watch. In the Apple Watch app, I select "My Watch" / "Passbook & Apple Pay". I tap "Add a Credit or Debit Card". From then on I just get the "waiting twirl", eventually the iPhone says "Could Not Connect to Apple Watch - Make sure your Apple Watch is nearby, powered on, and not in Airplane mode." ... which it is all three.
BUT, I'm successfully paired to the Watch. What do I try next?
Apple Watch, iOS 8.3