According to this FAQ page you can use Marriott Gift Cards at participating Ritz Carleton properties.
Q. Where can I use my Marriott GiftCard / eGiftCard?
A. Marriott GiftCards / eGiftCards can be used at any participating Marriott properties, including JW Marriott®, EDITION®, Autograph Collection® Hotels, Renaissance® Hotels, AC Hotels by Marriott sm, Marriott Hotels® & Resorts, Courtyard, SpringHill Suites, Fairfield Inn & Suites, Residence Inn, TownePlace Suites, Gaylord Hotels®, Marriott Vacation Club® or online at www.shopmarriott.com. Card may also be used at participating Ritz-Carlton properties worldwide.
Here's more than you care to know about the gift cards. Note that under Terms and Conditions it says: may also be used at participating Ritz-Carlton Hotels. So you may want to call in advance to avoid any headache.
Marriott GiftCards may be used at participating JW Marriott®, EDITION℠,
Autograph Collection® Hotels, Renaissance® Hotels, AC Hotels by Marriott℠,
Marriott Hotels & Resorts®, Gaylord Hotels®, Courtyard® by Marriott,
Fairfield Inn & Suites® by Marriott, SpringHill Suites® by Marriott,
Residence Inn® by Marriott, TownePlace Suites® by Marriott and Marriott Vacation
Club℠ and participating hotel outlets: retail, spa, golf and food and beverage.
Marriott GiftCards may also be used at participating Ritz-Carlton hotels. Card
carries no value until activated. Card is a prepaid card, not a credit card or
debit card, and is the property of and issued by MI Fulfillment Services, LLC.
This card does not expire. Card is not redeemable for cash in any amount except
when otherwise required by applicable law. Card becomes inactive upon use of all
card value. Card may not be used for deposit, advance purchase or to secure or
confirm a reservation. Each transaction will be debited against card balance, if
transaction exceeds balance, user must pay the difference. Lost, stolen or
damaged cards will be replaced only if previously registered. Value of replaced
card will equal balance on card at the time it was reported lost, stolen or
damaged. To check card balance, click here or call +1 800.442.6132. For
questions, please contact the Customer Service Team via email at Gifts@marriott.com or dial +1 801.468.4167
Monday–Friday: 9 am–7pm EST / Saturday: 10 am–4:30pm EST.
Given the season they've had, I'd like to see UNC win, but they have to take two straight from a good UCLA team just to advance, so it will be tough. All three remaining teams are deserved champs, so I'm ok with any outcome, as long as it's won - rather than lost. These guys are still too young to have a devastating error/blunder stay with them forever.