Guests of the Dolphin and Swan are not eligible to for the Disney Dining Plan, Julie. To take advantage of the dining plan, guests must purchase a vacation package that includes resort accommodations in a Disney owned and operated resort, and theme park tickets. If you choose to stay at either of those two resorts, you will not have a Key To The World Card either, as those are reserved for guests in Disney owned and operated properties.
There are, however, perks to staying at the Swan or the Dolphin. For starters, both locations offer excellent proximity to Epcot and the Boardwalk area. You'll also enjoy access to
Extra Magic Hours, complimentary transportation around the resort, and package delivery to your resort. However, if the dining plan is a deal breaker for you, you'll need to purchase a Magic Your Way vacation package through one of the Disney resorts. I hope that clears things up for you!