The fact that you "took the bump" is no reason you should not receive the miles from your original routing. The compensation you received for not getting on the plane was for "helping Northwest out of a jam".

Call Worldperks and simply say that you were rerouted and would like credit for the original itinerary. If you don't receive the answer you like, wait a minute and make the same request to a different agent. It's the flyertalk way.