I am aware that the version from GOG is technically 1.01 but I would like to install the unofficial patch.

I have the unofficial patch, but I'm not sure where to install it to. Is it just GOG/Evil Genius?

Yep. Just install it into the Evil Genius main folder.

Thank you kindly

Can you do this on the mac version? I know it uses wineskin to work, but not sure I can patch or mod it..
If u can, could anyone enlighten me?

To my wineskin experience, that is pretty possible. Just right-click the wineskin-app, click "Show package contents" and open the "Wineskin.app" inside. Then, simply install the patch.
Haven't test it, but I'm pretty sure it will work (if you are unsure, make a backup of the game before applying the pathc)

Hope that helps