Elemental Savant (Earth)

[da chicken]

We had a Ice ball and Bolt of cold for our wind savant.

Water is cold. Air is electricity. House rule?

 

[Tar-Edhel]

You are correct:

It doesn't state that only your chosen element is applicable.

Especially since Energy substitution is a requirement for the PrC. Every spell you know with an elemental descriptor can be changed to your element of choice at no cost.