This one?
Eh, might help a little I guess. Most of the time, twisting wires is done for long runs to either reduce noise being emitted from the wires, or more commonly, to reduce noise being induced into low-voltage/high input impedance wires (think audio).
I think the problem with that pic isn't whether or not you twist the wires, it's the placement of the antenna. For one thing, it is running parallel to the motor wires (albiet a few inches away). It would be better to mount the rx in the rear instead to get more distance from those motor wires. Twisting is probably helping, but still not ideal. For another, that's either an AM or FM radio (judging by the length). AM is
really susceptible to interference, and FM is a bit better, but not perfect. AM usually is affected by glitchy operation, whereas FM usually just gets washed out by the noise and has limited range.