Hi there, Maureen!
Pirates & Pals Fireworks Voyage is one of my all-time favorite experiences at Walt Disney World - you're sure to have a blast!
During your visit, the fun will begin 90 minutes prior to Wishes!. And the fireworks are slated to begin at 9:00 PM on September 29, 2012. Thus, you're looking at a 7:30 PM start time to your activity.
Even though the Wave and P&P are both located in Disney's Contemporary Resort, my concern is that you won't have much time to enjoy your meal. You'll need 15 minutes or so to head upstairs and check in; if you are seated immediately, you're now looking at about 45 minutes for dinner. That might be cutting it close.
Have you considered the Outer Rim in the Contemporary? This is a delicious quick-service option that has a variety of options, some rather unusual (the flatbreads are particularly delicious). You'll be in proximity to the check-in point, but you won't have the time constraints associated with a table-service restaurant. It might be a great alternative.
Have a wonderful time!
See you later, celebrator,
-Deborah B.