But... bears are sooo much better than elementals 
I spoke to the warshaper that I have played with, and he suggested Improved Multi-attack or Improved Natural Attack.
You might want to also direct your druid to look at the Nature's Warrior PRC after he is done with warshaper. Its abilities augment a warshaper well. (for example fast healing from different sources stack, so 2 from warshaper and 1 from nature's warrior)

I spoke to the warshaper that I have played with, and he suggested Improved Multi-attack or Improved Natural Attack.
You might want to also direct your druid to look at the Nature's Warrior PRC after he is done with warshaper. Its abilities augment a warshaper well. (for example fast healing from different sources stack, so 2 from warshaper and 1 from nature's warrior)