A 296

Your example spells do not provide "unnamed modifier types for bonuses". Instead, they both give enhancement bonuses, which you can read about here. Multiple enhancement bonuses never stack. These two spells also transform your body to provide natural attacks, but those are not bonuses. Because your body cannot support both transformations to your hands, only the latter will apply; this is an example of "One Effect Makes Another Irrelevant" in the magical effect stacking rules as detailed on page 172 of Player's Handbook.