There is no way they will give permission to you to grow them. They purposely spray them to prevent to much growth.
If a "wild" bine happened to grow up it, they may or may not do anything. Sure, you could harvest but I'm pretty sure you would get in major trouble if the utility came along and saw you with a ladder leaned against one of their power poles.
The other problem is hops have a hard time grabbing steel cable. They are bines with little hooks like velcro. Smooth surfaces don't do well. Find a dead tree or just a tree with a long branch and casually drop a line down from that to a "wild" rhizome you plant. You'll have a better shot.
Of course, if its on public property, someone else may harvest it before you.