Originally Posted by
hydrogen
Adding number to an AE booking is done manually at check-in. It results in AC*, regardless of one's status.
I think that if the person whose miles are used to make the booking has to be travelling for the AE numbers to go in correctly. Otherwise it won't. Also, I believe that the mileage redeemer's AE number is always attached to the PNR regardless of whether he or she is travelling.
This makes sense hydrogen. On the booking that it let me attach the aeroplan numbers, I was on the PNR and it was booked with my points. The other booking was booked with my points (and I was not on that PNR) but that one would not let me add the passenger's aeroplan number.