the challenge is that you want that oomph factor (not to detract from the blushing bride) as a backdrop to your photos.
there are a number of shrubs, trees and climbers that will be flowering in June but even if you were to obtain them now they would be quite small even in a years time.I hate to suggest it but for the pergola you might consider using artificial garlands, and around the floor area(in camera shot) pot-et-fleur containers of different sizes,filled with in-flower bedding plants and cut flowers for the height. As to the rest of the garden, unless money is no object you might consider moving the containers from point to point turning them so they look different in the photos.!!
Alternatively elope.