Your options are almost nil if you do not want to use AA/BA/IB. You could check out LANPASS, LAN's FFP. IB is not generous with giving miles to its cheap economy flying passengers, usually 30%. Remember that there is a daily LAN flight FRA-MAD-SCL which you could use to go to South America. All LAN intl flights give 100% miles for economy class travel in LANPASS. You need 80K kms in LANPASS to reach the status level that grants lounge access.