We were on Infinity in April. The ship was docked at the Aloha Tower Pier. If you go to GO.com and look for Hawaii - you'll come up with maps, guides, locators, routes, etc. Lots of good stuff we found on the internet prior to our cruise.
We stayed in Waikiki and it wasn't too far from the Pier - however, we had purchased transfers from Celebrity so can't help you with taxi vs. cruiseline xfers.