Marriott Gift Cards Can Now Be Used at All SPG Hotels
From the Gift Card section of Marriotts website:
Q. Where can I use my Marriott GiftCard / eGiftCard?
A. Marriott GiftCards / eGiftCards can be used at any participating Marriott hotel at these brands, including AC Hotels by Marriott®, Aloft®, Autograph Collection® Hotels, Courtyard®, Delta Hotels and Resorts®, EDITION®, Element®, Fairfield Inn & Suites®, Four Points® by Sheraton, Gaylord Hotels®, JW Marriott®, Le Méridien®, Marriott Hotels®, Marriott Vacation Club®, Moxy Hotels ,Renaissance® Hotels, Residence Inn®, Sheraton®, SpringHill Suites®, St. Regis®, The Luxury Collection®, The Ritz-Carlton, TownePlace Suites®, Tribute Portfolio™, W®, Westin®