Moles specialize in eating earthworms, seldom grubs. Beyond that, grubs are an uncommon problems in NW lawns.

Earthworms are the most favorite food of moles, although they will eat almost any insect including grubs. Nematodes need to be put into your soil when it is warm and moist, like mid June around here and that is really too late for them to be effective for this years crop of grubs. You could put Nematodes into your soil in mid September so the could get to next years crop of grubs.
Keeping in mind that gardeners have been trying to eliminate moles since at least the 16th century and the moles are still around there may be little, to nothing, we can do about them except coexist. The only people that are having any real success with mole control are those that sell you products to control them, that really do not work.