I called the AMEX Canada travel agent today.
What she said made no sense.

She first said that AMEX Canada uses its own travel booking service.
I then asked her if AMEX Canada uses SABRE as its GDS for booking. She said yes
She said that through this booking, I would get full benefits- points credit, all benefits of elite status.
But then she said that the bookings information are stored in expedia.

I totally got lost at this point what she was saying.

I say this because a few months ago, I booked a hotel booking (different hotel chain than the Marriott family of hotels)- a refundable rate.
She AMEX travel agent reassured me I would get full credit for points and benefits.
Twenty four hours later- no booking on that hotel chain web site.
I went back to the same travel agent- she called the hotel directly to see what was going on.
She found out that the booking would not get me any benefits
.
So I cancelled the booking and booked directly with the hotel - to be able to receive full benefits and credit for the night stayed.