Having grown Passiflora caerulaea (which is what I think that species is) from seed, I can tell you it didn't flower in year 1 but did in year 2 and is now like a blooming (pun intended) weed. Literally! It's sending up suckers in the lawn several metres away from the parent and if we let the fruits fall, they self seed like a 15 year old boy at a Beyoncé gig... Not too much further south than you but possibly enough to make a difference.
Our Wysteria sinensis also flowers every year and is small and not very bushy... Avoid high Nitrogen fertilizers near it and maybe give it a drop of tomato feed.
As Ruth says, lovely flower and well shot.
Just for interest, they're called Passion Flowers since the 3 clublike stigmas are supposed to represent the 3 nails used to hold Jesus on the cross. At least that's one theory!