Appears to be related to #3270653.
JmDNS is sending query packets on the first available interface regardless of constructor arguments. Responses are received correctly on the specified interface. setNetworkInterface() statements on MulticastSockets are being ignored; this may be a quirk of the socket binding rules used on the MacOS JVM.
This can be remedied by explicitly binding to an address in the MulticastSocket's constructor. Possible fix in supplied Eclipse .patch file (works for me, but only tested on one machine).