So an affiliate campaign says they do not allow you to keyword bid on their domain name or their trademark name, but this mean I can't add stuff to it.

Example:
Diet.com

I can't bid on Diet.com, but can I bid on:
Diet.com Reviews

Just curious. I am probably going to do it anyway, I just wondered if anyone knew. I am not going to ask the company because that would just make them watch me.

still not allowed.
if they check ppc engines you'll get flagged.