Since someone here mentioned price changes, I just looked at the Five Star web page and noticed that not only did prices change, but also the terms & conditions have changed. The T&C now include the following weaselly language:
"Itineraries involving airlines other than American Airlines or American Eagle may be accepted if flight departs or arrives from an American Airlines terminal
or is approved by American Airlines Five Star Service airport staff."
In other words, there's no rule anymore and the individual agents can decide whether they feel like giving you the service or not. I guess AA decided it was too much trouble to establish a consistent product with consistent rules, so they gave up and left it to the whims of the agents.
