I’m speedrunning this game on the Wii Version. It’s different but it’s the same game. If I submit a time will a new sub category be created for Wii?

sure

When I go to submit my run it still only says PC for the platform

Yeah, I would like to see a Wii subcategory, as I only have the Wii version and would love to try to speedrun this game, and not go out of my way to play the PC version.