You're moving to Argentina? Really?

I don't think it's a good idea to move your BAEC account to Argentina, just keep it in the UK and use the miles and status while last.
Based in Argentina, it's probably much better to join the LanPass program (I don't know if they do status matches, you could ask), because Lan flies domestically (as long as the government let them), regional and international all around South and North America, and some destinations in Europe. But is still in One World, so you can redeem your km (yes, we use kilometers down there), with other OW airlines, and there are a few credit card programs that

Check this blog out, is the roughly equivalent of Raffles', but for Argentina: http://www.sirchandler.com.ar/. It's in Spanish, but if you're planning to move to Argentina it shouldn't be a problem.