HOU Local Controller experienced a loss of separation involving a single engine aircraft conducting a photo mission and an air carrier executing a go-around.

Narrative

Aircraft Y was cleared into Bravo airspace to maneuver for a photographic mission. Aircraft X was on the RNAV approach to Runway 12R. Aircraft Z departed out the West Satellite departure corridor. The next departure was Aircraft XB out the South departure corridor. Aircraft Z turned through his assigned heading directly towards the preceding Aircraft Z. Immediately after calling the traffic and correcting Aircraft XB to the assigned heading/corridor; Aircraft X reported a go around due to an RA. As I looked at his position relative to the VFR Aircraft Y; it was close to the required 1.5 mile/500 foot or visual separation Class B separation. Traffic between Aircraft Y and Aircraft X was not exchanged on frequency. Aircraft X was given climb out instructions and handed back to the final approach controller for re sequencing. Recommendation; continue scanning entire control environment as situations develop. Exchange traffic early. Advise the maneuvering aircraft of the approach in use and restrict their movement along the final as required.