Don,
Forget for a minute the system you are working on, if you install a made electrode per 250, and bond it to the power grounding electrode system via the required bonding conductor (#6 CU), doesn't your new electrode become part of the overall grounding electrode system?? You COULD do this all around a structure and still call it the power grounding electrode system, right? So based on that you could tie the communication system to this electrode system anywhere along it. What am I missing?