Is the rising dependent on the combination of soda and Earth Balance, or can I substitute butter instead?

I second that -- the Earth Balance was probably used instead of butter to make the result dairy-free (so many who are gluten intolerant are also dairy intolerant). Having said that, I don't expect it will change the rise but wonder if it will make the biscuit a bit less flaky? (different fats can give different results). I'm not familiar with the recipe, so don't know if flakiness is one of the goals, or if this is more of a shortcake type biscuit -- if the latter, I'm reasonably confident there would be little to no baking impact of changing the fats.

You should be able to substitute butter