By the way, according to the MQ documentation ("MQ Using Java", Appendix F), the AdminObject that you have defined in wmq.jmsra-ds.xml is needed only for *outgoing* messages, i.e. those originating in an MDB and going through the resource adapter outwards in the direction of MQ. You write that your goal is "to feed an MDB", which I assume means that you want *incoming* messages from MQ to arrive there: your MDB is consuming messages, not producing them.
The JCA specification constructs are different for incoming and outgoing communications. The reasons for this asymmetry are a mystery to me.