I called after I had been a OnePass member for a couple of years and got one. I'm glad I did, I started a new job with a lot of travel and was able to use up all my upgrade certs. One thing, they were VERY strict about the non-transferable rule of it. To the point the gate person would say "look at number six on the back" without even looking up from their computer.
Anyway, I think it's all in how you ask...just call and confidently say you'd like to order one as opposed to "can I order one?".