AFAIK, close-recon aircraft (such as the Fieseler Storch, comparable in some ways to a Piper Cub) had a radio-connection to the Flivo, which was located very close to the front and working together - quasi embedded - with Heer units. In parallel, the observers in the aircraft would jut down notes and take pictures above target. After the first radio transmission, the notes would be dropped out of the aircraft close to the location where the Flivo was stationed. The Flivo would then pinpoint the described target location on previously made aerial photographs and reconfirm with the just landed aerial-observers to eliminate possible misunderstandings. Then, based on this information, either aerial strikes or artillery strikes would be effected.
It is to be noted, that the Fieseler Storch did not require any sort of airfield to operate. Any patch of level ground would do. With a heads-on wind, it needed merely 50 meters (!) of ground to take off and 20 meters to land. Its speed was very slow, too. As such, it was able to do very short range recon and to operate in very close vincinity of the Flivo detachment.
The Flivo was not necessarily fixed in his position. There were standard German halftracks (of the SPW 250 variant I think) which were equipped with the necessary radio equipment. As such, the Flivo was able to keep up with the front and movement of friendly troops (especially panzer spearheads).
I think, that the Flivo did not have a direct radio connection to bomber, fighter, or ground-support aircraft.
Nevertheless, the "reaction time" and relative precision of ground-support attacks (especially Stuka) was very short and good compared to everything else that was around until late during the war.
von Marwitz