Hi, did you buy this wisteria as a named plant from a nursery, or did you get it from a friend or a plant stall or similar? Wisteria do take a while to get to maturity but those grown from seed rather than cuttings can take for ever to flower!
As it's in a container, make sure it gets plenty of water in the late summer, as that's when the flower buds are forming.
What sort of fertiliser has it been getting? - something with plenty of potash in it might nudge it into action - I'd sprinkle some sulphate of potash around it, or you could use a rose or tomato fertiliser.
And I'm a bit confused by your description of the pruning - you say you pruned it near to the ground one year? What happened then? Have you pruned it since?
Wisteria needs pruning twice a year to encourage the formation of the side shoots that bear the flowers http://apps.rhs.org.uk/advicesearch/profile.aspx?PID=242 I know it says do it after flowering, but just go by the time of the year if it hasn't flowered.