Members of AA's AAdvantage program earn AAdvantage miles based on distance flown on partner airlines -- other than JetBlue. But it's not necessarily a 1:1 earnings situation. You'll earn a percentage of the flown mileage, depending on the fare basis, whether you're flying in a premium cabin, and whether you have elite status in AAdvantage. That percentage might be more or less than 100%, based upon those factors.
Flights on AA and JetBlue will earn miles based on base fare and a multiplier depending on your elite status, if any.