All YMCA-owned facilities in Canada recognize and honour your YMCA membership. Similarly, Canadian YMCA memberships are generally recognized and accepted by international Associations. There are some exceptions, so be sure to check with the YMCA you want to visit to confirm their policy.
For those in the Okanagan, the exception to this is H2O Adventure + Fitness Centre, which is a municipally-owned facility operated by the YMCA of Okanagan.