The Gallerist
Can I spend Influence to raise a different Artist's Fame than the one my action targets?
Several players agree that Influence boosts only the Artist whose Fame the action is raising; no official statement.
No. Influence only adds to the Fame increase that your action is already giving to one Artist. You can't spend it on a different Artist, and it only works during your own action. A promotion raises an Artist by one level at a time.