Bonding agents are not necessarily needed. The perforated plate needs to be brought up to temperature, then, the pressing of the wood heats the pellets and the steam generated from the pressing is what releases the lignum in the wood and makes the binder. That's mainly why moisture is somewhat critical.
I was thinking about commercial meat grinder plate for the pellet plate. Drilling all the holes twice in a blank plate can get old, depending on size of the mill.