Velocity seems to be loosely modelled on Airpoints. I dont know too much about Velocity (other than award costs are terribly non-transparent :evil: ), but I do know about awards on Airpoints.
Using airbucks - for domestic awards the award covers fare and taxes and surcharges (it is wrapped up the same as paid fares now), for international and partner awards the award covers fare but not taxes and surcharges. This is the case not only for the fixed cost awards (longhaul business and partners) but also for the airbuck replaces cash awards.