Thanks for everyone's suggestions.
All my guests liked it -- even my non-white drinking father. The crisp tartness balanced the rich sweetness of the corn soup and the carmelized onion frittata nicely, and the sophistication of the choice impressed them.
I gave credit to chowhound, of course!
I ended up serving the late harvest Zinfandel (J. Fritz Winery, 1997) with chocolate decadence (with fruit salad my mother brought instead of raspberry puree). It was only after I opened it that I noticed the back label suggests "pair with chocolate and raspberries"!
Of course now I have three boxes of raspberries. Time to make sorbet, using Caitlin's corn syrup tip.