https :// www . aircanada . com/content/aircanada/ca/en/aco/home/altitude/aeroplan/cibc-cards.html is an official site that explains these benefits in detail, in case someone tries to give you a hard time. Sorry, can't actually post the link until I have more posts.

For Priority Check In I just walk up to the counter and flash my card - never had any problems. Honestly, most of the time they don't even check my card.

For Priority Boarding, it's always been printed on my boarding pass without me having to do anything special.