Astropath effecting allied army reserve rolls

[Scootare]

Below list is Grey knights as "Primary" army and Imp Guard as allies for a competative 2K list.

Does the Astropath +1 to reserve rolls effect the allies in the list?
Also if one side of the force say the Imp Guard had a Aegis Defense Line and put the Coms' relay in there would it effect the other side and vice versa?

Grey Knights are allies of conveniance.

I am looking for a Imp Guard force to hold the back lines and the Grey Knights to be able to come in with a teleport homer and key in off the Stormraven teleport Homer where I need them.
Key to this list is the grandmaster making the Dreadknights scoring troops (D3 of them)

If it didnt work I could move the aegis defense line up the the grey knight side and com relay it I suppose and have the Astropath effect the Imp guard side.