Been to both many times and since the view from California Grill is more "unique", I'd recommend that.
Should add that unless you have a window table at either restaurant, you won't really be able to "see" the fireworks in the fullest sense. For that , you'll need to walk out to the observation deck at CG, or the porch area at Narcoosee's. It's what we do and what most other folks seem to do.