a question about grapes, about plants that were cut way back [View all]

About 4 years ago I planted three grape plants in the same place. I wasn't thinking of how big they'd get, I was still new to gardening then. Well I built and rebuilt little walls of twigs and wires that just fell over, and then finally last year we built a big wood trellis for them, which is what we should have done in the beginning, but oh well.
So when we did this I had to untangle them from all the junk holding them up, so I cut them back almost to nothing. That's been almost a year ago and since then they've grown a LOT, already filling up the trellis. But there was no fruit last year, not one grape.
Did I cripple all three plants by cutting them back so much? Or were all the vines too new to make fruit? and this year they'll make grapes? Any idea?
TY