I recently booked flights on China Airlines and KLM, and was able to add my SAS Eurobonus number during the booking process.

Just saw that they have now been added to "My bookings" on my SAS account and when you click the "show" on each flight, it shows exactly the booking class. I guess it is a good way to check if we are booking the right booking class or not. Some airlines allow free cancellation within 24 hours of booking.