The Collectives are separate entity and essentially a sports agency. Spyre, again, doesn't legally pay anyone to play for Tennessee, as far as I am aware.
The general fund paid to players comes with the expectation of using that specific players Name, Image, and Likeness for advertising, jersey sales, autograph signings, etc. It doesn't matter if the money comes from boosters or not. It matter's not how a company generates money as long as it is done legally (which it is). And Spyre can distribute that money to it's clients in any matter they want.