I've been playing with a single (Very Expensive) skein of Southwest Trading Company's Bamboo Yarn, and I'll vouch for its durability. Not sure if the Joann's bamboo yarn is similar, but I frogged the same skein no less than 6 times just playing with the yarn to see what it would do with different stitch patterns and different size needles, and other than a little extra halo that was barely visible, it was completely fresh and new looking. One of the things that came out of it was a cell-phone cozy, because I knew it'd look delicate but would stand up to lots of abuse.
Oh, I agree completely. I made my friend's puppy a sweater from that yarn. It's been on the dog (being chewed) for a few months and still looks pretty nice. I made her an acrylic sweater at the same time, and it looks really rugged.