After reading the above posts, I decided it was time to add my IHG card to Apple Wallet. I woke the iPhone, went to the Wallet app, pressed the plus sign (+) near the top right of the screen, and followed the prompts. The iPhone read my name, the card number, and the expiration date off the card; I needed to enter the three digit security code and accept the terms. My only confusion was trying to verify which card was the default card; as far as I could tell, the only place to get that information is from Settings > Wallet. I could not find it in the Wallet app itself.

Good luck.