I received a book today that had a piece of tape on the bottom of the binding.  That didn't bother me, until I started to read the book and saw that the cover had torn away from the binding and the first 79 pages were not attached to the binding at the bottom, either.  I have never "rwaped" a book before, and really feel bad about it, But this is the Fourth book I cannot re-post because they have damage that I didn't notice until too late to complain.  So, is it a rwap?

Yes. Pages cannot be detached from the spine.

And don't feel bad. Why would you feel guilty for questioning someone that sent you something like that? They're the one that's probably biting their nails and hopping you'll mark it received before you notice the damage.

It sounds like it would be a RWAP situation. Binding must be intact with no separation and your description sounds separated. A small amount of fraying at the spine is OK, but it doesn't sound like you are describing fraying.

resolved- thanks for advice!

What they said about page separation and spine damage.  Also remember, tape cannot make a book postable.  Visualize the book condition without the tape, if it's covering tears or separations that require RWAP . . . the tape does not change the status, it merely protects the book from further damage.