I combined a refare voucher, a customer service voucher and a Chase Visa voucher on a two person PNR. The CSR told me I could not do this over the phone, or through ticket by mail, but it would be possible at an airport counter "if you get an agent who knows the system well." It wasn't very reassuring, but the friendly staff at BWI were able to ticket my reservation. They ended up having me pay for one of the tickets, with two vouchers combined, and the other with the other voucher, with the remainder of both tickets as two small credit card payments.

I'm not sure where the voodoo magic came from, but the agent was able to keep us together on the same PNR. She agreed with the assessment of the CSR that "this was not possible through ticket by mail."

It was worth the trip to the airport -- my non-status companion and I cleared with 500 milers cleared at my window.