Wirelessly posted (iPhone 3G: Mozilla/5.0 (iPhone; U; CPU iPhone OS 3_0_1 like Mac OS X; en-us) AppleWebKit/528.18 (KHTML, like Gecko) Version/4.0 Mobile/7A400 Safari/528.16)
You must book a full Y fare, which is the most expensive coach fare.
I do not recall the redemtion procedure as I have never used it. If you search, I'm sure the answer is out there.
Good luck