Well I just got bumped last week in Chicago.. the delay was going to be 4 hours, so they offered $300.00. I think the original flight is 6pm but the bump flight was 10pm on American. I luckily was connecting, so I bumped to another flight 2 hours later, non-stop, and first class.. got to LAX only 40 min later than scheduled... with $300 in vouchers

But I did remember him saying the hours and the dollar amount were linked....