For the record, I asked the ticketing agent, who was as sweet as can be.

She wasn't quite sure of how all the rules intersect and tried to add my FF number in to get me the bag free. When it didn't take, she said she could bring her manager over to override, but I said it wasn't a big deal, and I just paid it.

Afterwards she told me with a wink my friend should make me her regular +1 so I can get 2 bags at 70 free always.