Not Tarantino, Geffen was an established producer before Tarantino even got started and it says "The billionaire producer still controls Hollywood and the music industry." and I don't think Tarantino has ever been involved in any meaningful way with the music industry..

The list of Billionaires in Hollywood isn't that long so even If I'm wrong it would be a short list(with probably a few added to it that are in reality billionaires just not on any official paper, and Geffen definitively fits the bill in that regard)