Does orbital direction of a planet affect its synodic period as seen from earth?

Yes

Explanation:

Yes, the orbital direction of a planet affect its Synodic period as seen from earth. The synodic period of mercury is about 116 days on Earth. Whereas the sidereal period of mercury as seen from Earth is 88 days. This difference is caused by the simultaneous motion of Earth in its orbit. Hence we can say that the orbital direction of a planet affect its synodic period as seen from earth.