Hello, Megan!
When you book your stay at a Disney Vacation Club resort through RCI, just tell them that you want to purchase the
Dining Plan at that time. DVC Member Services tells me that RCI will contact them, at which point your stay will be arranged, if the exchange is available, and you'll be able to purchase the Dining Plan at that time.
You're going to love the value that the Dining Plan affords your family, enabling you to enjoy some truly fantastic meals at great savings, too. Take a look at the restaurants you'd like to sample while at Walt Disney World by heading over to
Walt Disney World's website. Once there, you can browse through parks to see your dining options, then click on some sample menus for a better idea of where your family can find some new favorites!
Have fun planning your stay! Be sure to send more questions as you think of them, too! I'd love to help you plan your stay at Walt Disney World!