I wouldn't want access as a bonus. I prefer cash for bonuses .

That said, I do often ask for access to a site if I'm going to try and promote it heavily. I need to know what I'm selling, so I can describe it accurately and make my visitors happy with their purchase and hopefully rebill later on. I will and have promoted programs that gave me access much more heavily then those that refused to grant me access. I almost always promote Platinum Bucks and not Top Bucks, simply because of that reason. So, yes, I'm small potatoes yet, but I do long term SEO, and a year from now I expect to be getting a lot of traffic for the sites I'm building today. And guess what, those sites are built around PB sites

That said, I don't think access should be granted automatically. I think it should be based on some sort of relationship, where the sponsor marks an affiliate's potential to bring them sales down the road.