Zone Controller T-Stat Wiring w/ 24V transformer, isolation relays for 2 zones
That is correct, yes

That is a correct way to wire the coil-sides of two isolation relays -- one end of the secondary provides C to the relay coils and thermostat C wires, while the other side of the secondary provides R to the thermostats, and the W wires from the thermostats go to the free terminals on the corresponding relay coils.

The relay contacts then simply go in parallel -- this means that a call for heat from either thermostat will fire the boiler.