Hi Carolyn,
I'm going to assume that in your question you meant that you will be dining at the California Grill on November 30 and not September 30, since September has passed and the next month on which the 30th falls on a Sunday is November.
If you check the Magic Kingdom park calendar found
HERE, you'll see that Sunday, November 30, 2008 is a night when the regular Wishes fireworks are not shown at all. Instead this is a night that Mickey's Very Merry Christmas Party will occur. The exact schedule for this event has not yet been released, however, my very educated guess, based on the timing of past parties is that the Christmas Wishes fireworks will be shown that night at 9:30 p.m.
This is perfect for your 9:20 reservation. If you're seated by the window, you're all set. And if not, you can bring your dinner drink to the observation deck to see the show before your main course.
Enjoy!