MilesBuzz! - American companion pass

If I upgrade my AAdvantage card to Platinum they will give me a compaion pass. Do these work in Business and International? What are the restrictions? Thanks.

Citibank may offer more than one companion pass kind, but the only one I've seen so far is the domestic companion pass, valid in the lower 48, and only on economy fares V, K, Q, (and another one, M?). The fare restriction makes these certs a lot less desirable than they used to be (once upon a time, they could be used on any discounted econ fare). It says right on the cert that, in some cases, discount fares provide a better value.

Citibank take a look at your AAdvantage profile and will send you an offer to match your flying. I have been offered companion passes to South America and Europe. I have never seen it for business of first or full Y.