Thank you all very much for the help. :-:

I've had a nosey round on BA, and it would seem the Iberia flights to GYE are actually Lan Chile so it's economy and business class only. But Lan Chile business class gets OK write ups on here, though they are from a few years ago.

There seems to be loads of availability as well, whereas there is hardly anything with AA. Maybe that's a bad sign though!