Host > Features
Scroll down until you see Reputation Settings
At the bottom of the aforementioned section, you'll see these two settings.
Min. Value to allow Add Reputation:
Check if the User matches minimal requirements for voting up.
Min. Value to allow Remove Reputation:
Check if the User matches minimal requirements for voting down.
But as tha_watcha mentioned, you do have to be logged in as a Host user to see Host settings.