Like bins, street lighting normally covers the highway and responsibility would usually sit with the body who has the responsibility for the path or road (highway).
Things like bins and lights are there because of the footpath or road, so responsibility for these would rest with the owner of the street (highway) for example, a full bin in the street would be dealt with by the body with responsibility for the path or road. This is usually the Council. For more info and to report issues with TCBC lights, see here:
Report a faulty street light, illuminated bollard or traffic light | Torfaen County Borough Council.