Colston's Almshouses are a stone's throw from St. Michael's Church on St. Michael's Hill. Could he have been buried there?
Snippet of info re church:-
The Bristol Town Plan of 1884 shows there were several areas surrounding the Church set out as graveyards, all by then disused, but not - apparently - closed by 1854, under the requirements of the Burial Act of the previous year, since the above list of parish registers indicate burials were seemingly still taking place as late as 1878.