nope, that won't do it on several fronts.
first, your photo transistor is wired wrong. emitter to gnd, collector connected to +V via a 10K resistor (you can play with this value for more sensitivity). input to the avr is from the collector. It acts like a switch. when it's off (darkness), the collector to gnd voltage is close to +V. When its on (light), the collector to gnd voltage is very low because the transistor is conducting. it's just like a pulled high switch, in that regard.
secondly, your led resistor seems a bit low. your 6VAC is going to peak at 1.414*6 or 8.5V. The 14001 will take a .7 forward drop and the LED has a max Vf of 1.4. That leaves 6.4V. I would target an If of 10 mA so that means a 640 ohm resistor. next standard size up is 680. If you want 20 mA If, use a 330 resistor. While the led can handle higher, I wouldn't push it.