If you have to chance to bond to them, you should probably take it. Just make sure that the steel rods are properly tied (bonded) to each other so that when lightning strikes, there won't be much arcing within the framework.
As for non-conductive: no way!
Both absorb lots of water, form ions, and are very conductive.
This is good in that any current getting to the steel will find a huge footprint to dissipate it into the ground.
When bonding, avoid steel contacting copper or anywhere the water can come into contact with copper and then with steel.
