I would certainly mention it if the chance came up. I agree - if the company is anti-cyclist, would you really want to work there?
Of course, it depends a lot on the style of interviewer, but generally if they want to make you an offer, I find it very easy to bring such matters up. They'll discuss stuff like "where do you travel in from" where it's easy to say where, and then describe your likely journey in and say that you're a cyclist. I don't see how any decent employer would be against that.