We had this same thin happen with us for our August trip. It was me, DH and DS2. DS's name was on the main reservations, had own air ticket and everything. Got nothing from DME for him. Even tried to request extra tags. Was told that only guests with air tickets could have the DME tags???? Once I pointed out that he did, infact have his own ticket for the flights, they said they would send out more tags. Never got them.
When we got to the DME desk at the airport, I just told the CM what had happened, and there was no problem, since DS was really on the main reservations. Fortunately we had enough of the DME tags for all three of us, otherwise we would have had to turn over the claim tickets and give a discription of the pieces without the tags...so we were told. Just glad all worked out in the end, with no problems at all!