If you haven't already, check out the YK Climbing Club Website (http://ykclimbingclub.com/). I have generously donated a crashpad to the club (I know, one step closer to sainthood) so drop them a line if you're looking to do some bouldering.
In conclusion, Yellowknife has a lot to offer in the way of climbing. The climbing is there, it just needs some deicated people to develop it!
All the best,
Route development on the Ingrahm Trail (5.6-5.11 plus....oh bueno!)