I tested it. With the Swiftly Forgotten skill at rank 1, my bounty should decrease by 35 every 5 minutes. In fact it decreases by 15 every 3 minutes.
Either the code is buggy or the bounty decrease rate is scaled down from v16 (the character I tested on is level 21), in this case the tooltip is not adjusted properly.
Is someone else experiencing this as well? It would also be interesting if people tested this on different character levels.
@ZOS, it would be great if the bounty tooltip in the Character menu would show current bounty and heat decrease rates and show the duration until the bounty is fully decreased.