ok...

So I have an HTPC in the office, with a Powerline adaptor hooked into the "grid" which contains all our media stored in a Plex media server. The router is in the lounge connected to a WDTV media player via ethernet. WDTV connected to an AV receiver via HDMI, which is connected via HDMI to Sony Bravia TV. 

My question is does streaming or transferring files across the local network from the HTPC to the media player renderer (non Plex as there is no app sadly) contribute to data usage from broadband GB allowance from Telecom?

My thoughts are no it shouldn't because it is not a download from the internet, effectively it is just moving files from one network location to another. Or am I wrong?

TIA.