I saw your question and went looking for my book on flowering crabapples and got sidetracked. Bill Valavanis had a crab that was flowering and it was featured in his Creation Pruning sections of International Bonsai for several years running. It stopped flowering after the cutback and he was told it had to reach a certain number of nodes before it would flower again, so he was going to experiment with not pruning it for a few years.
Wisteria can take decades to flower from seed, and one reason why a lot of these species are propagated by grafting.
You might drop Brent Walston an email. He has a nice page on
crabapples here
Regards,
Matt