If your question is "Can I use the rebar in place of a ground rod at the pole?" the answer is maybe. As far as I know, Code does not require a ground rod at a light pole. An EGC is required back to the power source and the metal pole should be bonded to the EGC, same as any metal enclosure.
The rebar and concrete base are probably a better ground connection than a rod due to the much larger surface area in contact with the earth.
But if the engineer or owner wants a ground rod to feel better about lightning protection or safety, you may have to put it in.