STS Controller described an apparent loss of separation event when observing an aircraft initiating a go around because of departure traffic spacing.

Narrative

At the time of this incident; I was working Ground Control/Flight Data/CIC combined and I was busy taxiing aircraft and augmenting/cutting the ATIS. I saw aircraft X; a twin Cessna; off the departure end of Runway 14 whom I assumed had done a low approach; touch and go; or go around. Aircraft X was at about 1;000 FT and appeared to be climbing 1/4 mile off the departure end of the runway. Behind the twin Cessna; I witnessed aircraft Y; a Bonanza whom I had taxied out shortly before; depart. I did not think anything was amiss because the Bonanza had not entered the runway until the twin Cessna was at least 3;000 FT down Runway 14. Local Control gave no indication that the twin Cessna had gone around; because Local had forgotten them and cleared the Bonanza for takeoff; thus prompting the twin Cessna to initiate their own go around. Whenever possible; [I recommend] having uncombined positions so that an extra pair of eyes/ears is possibly available to assist Local Control when traffic picks up.