1. Rhizomes will not likely go that deep.
2. If they did go that deep, they would not crush, infiltrate, crack, harass, intimidate or otherwise bother the PVC.

Is there anything else that concerns you about this?

The problem may be that it is harder to fix you
pipes when they have problem under, specially
clumpers. Dealing with mature rhyzomes of clumper is even
harder than concrete. In case the rhyzomes
mix with pipes and there are some couplers, it is
possible the rhyzomes may decouple pipes, under the
"concrete" like rhyzome.

coolshare-
I agree that if you happen to have a problem directly under a bamboo a repair would be harder, but I had over 2000 feet of PVC sprinkler pipe and fittings in and around the bamboo at my last house and never had a problem with the bamboo. The only problem was me when I was planting something new and managed to nick a line with my shovel.

Thank you so much for the info and opinions. I think I'm going to go ahead and do it. Having bamboo is definitely worth the risk of sometime in the future messing up one outdoor electrical line. Thanks!

voxfire-
If you ever have an electrical problem because a bamboo got inside your otherwise intact PVC piping, I'll get on a plane and help you dig the line up and repair it!

thanks, kudzu! :-)