I would assume the 15% discount would apply to the 1 person with the Premium Annual Pass & paying the bill.

Most of us carry cash and add to the pot THEN only use the 1 person with the AP. This is how we've done this when we go with a group of ten!

You could always ask before ordering with your large party on splitting check and applying each persons AP discount...

if possible. Seems like too much work on their part but never hurts to ask.

Maybe others have better ideas.

Good luck!