I received a companion certificate for the one-year anniversary of my MP Platinum Visa card. When I got it, I didn't look at it very hard since I had used other companion certs that didn't have restrictions on them. I looked at the cert again yesterday and saw that it only works when booking fares based upon "zones". Unfortunately, I must have tossed the info that came with the cert that shows fares for the zones. Can anybody share this info with me?

Thanks.