If you have 2 zones with the same watering needs, they can both be wired to the same terminal on the controller, and both will receive identical watering schedules.
The think that determines if there will be enough current in the wire going to valves to open and close more than one valve at a time is determined by the length of the wire, and the wire size (diameter). If you find the wire size you currently have is causing too much voltage drop to activate both valves simultensously, you can run another wire in parallel to the existing wires to carry more current to the valve, OR, you can replace the existing wire to the valves with a larger guage wire.
You should have a pressure regulator on your irrigation system, so the pressure hitting the valves is around 70 psi. These valves are not designed for high pressures, and without a pressure regulator, you may experience difficulty in getting the valves to open OR experience early failure of the valves.