It is not the Disney Dinning plan and there is an explanation for it. The way the Disney Dinning plan is currently, All hotels owned by Disney are part of the dining plan when it comes to table services, counter services, and a number of snacks. That means while 3rd party restaurants in the theme parks and downtown Disney are the Disney Dining plan, it is different for Hotels that aren't owned by Disney.
While the Walt Disney Company built the Swan and Dolphin, they are not the owners of the hotels and that means Swan and Dolphin doesn't have anything on the two hotel's property in terms of food that is on the Disney Dinning plan as a result. Tishman Hotel Corporation owns the hotels with them operated by Starwood Hotels and Resorts Nationwide under the Westin brand.
Disney gave Tishman a 99 year land lease also.