I'm pretty sure it does as I noticed a difference between my level 18 toon who has a Quiver but only 6 levels of monk VS my other shuri thrower who doesn't have a Quiver and has 18 levels of monk. Both were max Dex.
Now how about Gilvenors and Quiver? That should be stacking speed goodness from level 18 onwards until Blinding Speed... if only we were all that lucky to have both (actually all three items) in the bank =D