Warhammer Fantasy Tournaments Statistics
Rankings HQ is probably the closest you can get to what you are looking for.  There are a couple of disclaimers to add though.


The pool of ranked games is going to be pretty small. 
The ranking is elective, so there's going to be lots of missing data. 
It won't track information about particular tournament formats, just the results.


Torrent of Fire is a paid service that comes closer to what you want, but it's only for 40K.  I think they where planning on branching out to Fantasy. With Fantasy's declining popularity and GW's current financial implosions, I don't know if we'll see that happen any time soon.