So due to a combination of weak search-fu and a bad official website, I can't back this up...
But I'm pretty sure I read somewhere that a card that affects a type of Bakugan also affects all evolutions of that type, i.e. Tigrerra affects Blade Tigrerra. I don't see why Preyas' evolution would be excluded.
There was an "official" answer that confirms this, i believe its in the faq of the official site.