Both the recipe vendor and the pet vendor are up on the hill over the big 6v6 arena (Field #4, I believe?). The Recipe vendor (and a supplier) are near a cooking fire on the southeast corner of the field while the Pet vendor is above the northeast corner of the Field. (near a pen where you can see the tiny chicken types)
I agree that it would be nice to have blue barter flag markers on the mini map for these.