I know, real cooks don't use this cheap version of wine but would it make a difference in the dessert?

I would use either the brandy on it's own or a combination of both liquors.

Don't use the cooking wine - it will ruin the taste of your dessert. You could add a little brandy (not too much because it can be strong) or just not add any alcohol - I've had some that used vanilla extract that was good.