The 8148E is what started the burner and circulator before by the thermostat which is a switch between T and T on the 8148E.
So the Taco zone valve terminals 2 go to one T on the 8148E and the Taco zone valve terminals 3 go to the other T of the 8148E. Both Zone valve 2 terminals go to one 8148E T terminal. Both Zone valve 3 terminals go to the other 8148E T terminal.
One AT72 transformer terminal goes to both zone valve terminal 2's. Yes the terminal 2 of the Taco zone valve does double duty. The other AT72 transformer terminal goes to the two R terminals of the two thermostats. The W terminal of one thermostat goes to the 1 terminal of one Taco zone valve. The W terminal of the other thermostat goes to the 1 terminal of the other Taco zone valve.
This is what is on the yellow card on the head of every Taco zone valve and on the box of every Taco zone valve when you get them in the box.