The Marriott resort at Marco Island is in the process of construction/re-branding that will result in it becoming a JW Marriott hotel/resort in Jan '17. Guests at Crystal Shores can use the public facilities (restaurants, spa, etc) that are open at the hotel but I don't believe they offer discounts anymore and I'm pretty sure you can't charge the services to your Crystal Shores folio. Still, the Crystal Shores concierge should be able to help you schedule any services.