Hi John!
I would still definitely highly recommend the Disney Dining Plan for your Walt Disney World vacation during the Food & Wine Festival.
Most booths around World Showcase will have offerings that are purchasable using a Snack Credit from your plan, any many Guests use their Snack Credits for precisely that reason during the festival!
If you plan to do lots of great dining and plenty of sampling and snacking throughout your stay, consider the
Disney Deluxe Dining Plan which will allow you 3 Meal Credits at your choice of Quick Service or Table Service PLUS 2 Snack Credits, per person, per night of resort stay. This plan will save you 20% or more on all of your dining, and allow you the flexibility to enjoy as many samplings 'around the world' at Epcot as you choose, while still having 3 full meals daily. Keep in mind that the dining plan is a 'pool' of credits for use during your stay, and not a daily allotment. You can use more than 2 Snack Credits per person during your day(s) at Epcot.
If 1 Snack credit per person per night of stay is sufficient for you to use at the festival, and you plan to purchase other additional meals and snacks outside the plan, consider the regular
2012 Disney Dining Plan which provides 1 Table Service Credit and 1 Quick Service Credit, per person, per night of Resort stay.
See all the details about the plans on the Disney Dining Plan page of the Walt Disney World website.
Wishing you a simply Magical time at Walt Disney World John!
Kirsten