Collet House used to be some offices for Wessex Trains. I know some ex-Wessex Management were based there until just before the FGW local management restructure - I think traincrew might have been based there too. Bristol & Exeter House now stands empty pending redevelopment. The latest I have on it was that Planning Permission was granted subject to conditions following numerous appeals by the developers GVA Grimley using the company name 'Bristol Exeter House Ltd.'
Appeals for "Improvements to the curtilage of Bristol & Exeter House and Temple Meads Station including the creation of a new public square associated with the wider redevelopment of land at Temple Gate" and "Demolition of existing buildings and re-development to provide a mixed use scheme comprising office (Class B1), residential (Class C3), retail (Class A1),restaurants & cafes (Class A3) drinking establishments (Class A4) and community (Class D1) uses, a new public piazza and associated landscaping, basement car parking, servicing, access and ancillary works" (the latter for Collett House) were both withdrawn.