Booking on co.com is immaterial for partner flights. As long as the fare class purchased on the partner flight is listed as earning 100% EQM's, you will earn 100% EQM's. For example, KL B, M, H, Q, E, K, L, and T fare classes earn 100% CO EQM's irrespective of where they are purchased. Just check the earning charts on co.com when considering purchasing a ticket.