So I have A-List and Companion Pass for this year. I have an upcoming nonstop trip with a companion friend. Flight is at 8:45pm. We now want to take the earlier nonstop flight at 12:30pm. I know I can do a same day standby and take the earlier flight (with seat availability) and have done so several times by myself. I've never done same day standby with a CP.

My question is that if there are available seats for the earlier flight, does the same day standby rules apply to my CP friend as well since we have to both travel on the same flight? Or do they have to pay some fare difference?

What if the flight was booked using rapid rewards points?

Or is it not allowed at all and we have to stick to our originally booked departure time?