There is not a lot of prog rock in the St. John's scene... There's a lot of trad-ish bands, there are a good few indie singer/songwriter types, some shitty emo/screamo bands, a few punk bands, a few metal bands, a bunch of generic rock rock bands, a few lonely "other" band types, but not many good ol' prog rock bands.
There is one very notable exception though in the AE Bridger band. Although I'm certain he'll spit on me for referring to him as prog rock, in my mind he embodies many of the better qualities of tradition 70's prog rock. Complicated song structures with heavy dynamics, strong virtuosity in playing, and a strong inclination to experiment in the studio and on the stage. If I had to relate AE Bridgers music to other artists I'd say they're like if Robert Fripp and Fred Frith had joined the band Television back in the 70's (if that makes sense). I could list a pile of different artists I can here in his music but AE Bridger definitely does his own thing. Anyway, you can find out more about them at their Myspace page and here is a video I took of him at The Ship a couple of weeks ago.
And here's their official video for "Stretch-A-Sketch" off their new album "I am a Ghostly Leech"