So on the PUJ-YUL flight I clicked both the 'sign in' section on the main page and the little man. Both bring me to the spot where there is only 'WIFI onboard' sign on.

There's two areas to sign in, one to the right of the options to purchase, and one on the top right (little man - log in to account). Both of these lead to a WIFI onboard only sign in (no aeroplan sign in).

I'll try to take some detailed pictures if this happens on my next international flight.