Hi Zach,
Your transmitter already has an electret microphone amplifier, so why do you need another one for a parabolic dish? Just connect the electret microphone to the transmitter with some shielded cable and mount the mic at the focal-point of the dish.
Your transmitter will probably work much better, especially when the battery is low, by adding a 0.01uF capacitor and a 100uF capacitor, both connected from +9V to ground.
The mic amplifier will have more gain so that the mic is even more sensitive, by adding a 100uF capacitor across R5.