I've seen this bus show up on Expertflyer as part of a Swiss availability search from Ottawa to ZRH, via YUL. The trick is you have to search from XDS (Ottawa Rail Station), where the bus leaves from, rather than YOW (the airport).

I'm guessing you my have booked through Aeroplan, and would guess that their site wouldn't support this, but it might be possible that an agent could query XDS and the "flight" would show.