It may take 15 years for it to bloom - just leave it alone and it will bloom when it is mature enough.

Based on the experience of others, you may try the following: prune all vines back to 2 buds per shoot in early Spring before dormancy breaks, prune some of the new growth back in mid summer, don't feed it any fertilizer unless it is low nitrogen/high phosphate, and hit the lower trunk several times with a rubber hose/rolled up magazine to stress the plant a bit. Quite often stress jump starts the plant into blooming. Good luck!

Hi,
I have a wisteria that started blooming 3 years after I planted it. I've been training it as a small standard. I cut it back a lot all season long and I get tons of bloom. I just prune where ever there's growth I don't want. Here's a pic from last year.
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Other things I did from reading before I planted.(I know this too late for you, but it maybe helpful to others.) I put it in clay soil and did the bathtub effect method of planting which I would recommend not to do to anything but a wisteria, lol. I dug out a large hole and put good soil in it and planted the wisteria. This causes the roots to have a nice place to grow a short distance, but then they have difficulty spreading beyond into the clay barrier. It seems wisteria likes to be root bound. That is why people often see it blooming in a pot, buy it, and when planted out into the garden, it fails to bloom.
The other thing I've read is don't fertilize. It causes more growth and no flowers.
Remy