Not every tree is worth the effort to collect, but you must think it has some potential. With only a 3 inch diameter trunk, I would only collect it if the first 6 inches of trunk are interesting. If the lowest segment is arrow straight, without branches, I'd probably pass on it. You want a trunk that is thick enough for your idea of what the finished tree will be, and you want to have some of the branches you will need already in place. Yews don't grow fast enough when in pots or nursery containers to dig a little one up and hope to grow it into a bonsai.
Yews do back bud. even on older wood. If the side of the trunk with no foliage did not die, but rather is just too shaded to have foliage, yes, it could work.
Without a photo, hard to say one way or the other.