unclear about Cinemaplus service

Had my DIRECTV system installed a few days ago and loving it so far. I've been reading these forums but am still unclear about the Cinemaplus service.

3 receivers total:

living room = HD DVR

bedroom and basement = HD receivers

Whole house DVR service

DVR is connected wirelessly to home network and has been working wonderfully. I can watch recorded programs on both of the other HD receivers.

My question is how do I get on Demand/Cinemaplus on the HD receivers. I get it on the DVR. I'm assuming I need to connect the HD receivers to the internet as well? I fooled with it a bit today but no luck. Each of the HD receivers has a DECA box with a coax and an ethernet cable that go into the receiver. 

Just trying to sort it all out, any insight greatly appreciated.