paralell in which plane? therein lies the problem. the axes could be paralell in the "X" axis but 90 degrees out in the "Y" axis and still be considered parallel. if you describe them to be parallel to two mutually perpendicular planes then you have the parallelism controlled but your target zone is no longer round (which makes the tolerance stackup calculation much easier) it is square. if the goal is to have two bores concentric with each other, this could be either a concentricity or a runout call depending on what references you have and whether you are also trying to control "roundness" of the holes as well as the straightness (runout does these too, concentricity does not. therefore runout is usually preferred.). also, if they aren't referenced to the perpendicular face they may not be perpendicular to it.
it's a pretty good book, and Mr. Foster is a pretty good teacher as well, but not cheap. The list price of the book is $39.95 USD, ($59.95 Canadian). But I'm sure if you prowl the online used book sellers you can get it cheaper.