Zant had no power before Ganondorf bestowed it to him.
Zant explicitly notes that his powers are that of his god's (Ganondorf).
Ganondorf has been seen utilising the same Twilight magic Zant can, albeit not in the way Zant did because it would be redundant (You fight Ganondorf in the Twilight realm, what Zant does is merge the realm with Hyrule).