Nope. AA Flight Number AND AA Metal DEPARTURES only. No AS codeshares on AA metal and No AA codeshares on AS metal.
OK...so when I head south and fly KTN-SEA-DFW, with the SEA-DFW leg booked on AA ticket and AA metal, then I can use the BR?
Not that I would, but it's nice to know in case I get tired of my usual SEA hangouts.