Internet fares are discounted because AS doesn't have to pay anyones salary to speak with you about the fare.... there is low overhead. Therefore, as soon as you have to talk with someone (over the phone or at the airport) you are not able to book that fare.
So, I guess this makes the $25 discount pretty worthless unless you buy last minute fares or flexible which are the same price online or at the airport. Suggestion..... If you've got any of the old paper companion certificates (which require ticketing at the airport anyway) use the $25 discounts for the full fare pax. You're already at the airport. Also, you can check the fare rules online. If it doesn't say internet only fare, you may be able to purchase the same fare at the airport with the coupons. I'd call reservations about a specific fare first though.