With a separate transformer in the same room as the valves, you either need 4 wires, or a relay and 3 wires.
second transformer + 4 wires+ zone valve:
second transformer + 24 VAC NO Relay + 3 wires + zone valve:
With a separate transformer at each thermostat, you’d only need 2 wires, but then you have a wire running to each of the thermostats to a wall mounted transformer.
The diagram would look like this:
