Dose Righteous Might stack with polymorph spells?

[Mysterious Stranger]

I was working on a high level ifrit oracle of flame with the form of flames revelation. He will be taking the favored class bonus to allow him to be considered 18th level for form of the flames so he can become a huge fire elemental. I was looking over his 5th level spells and the Righteous Might is not listed as being a polymorph spell. If that is the case the spells should stack and allow him to become a Gargantuan fire elemental.

[Taenia]

keep in mind that size bonuses from both spells dont stack and you can not stack size increases so you cant get any larger once a huge elemental

[Gauss]

No, polymorph spells specifically exclude size changing magic.

CRB p212 wrote:

In addition, other spells that change your size have no effect on you while you are under the effects of a polymorph spell.

Righteous Might has no effect while polymorphed.

- Gauss