Hi Iwerne, welcome to OpenStreetMap! I just wanted to check whether you have permission to copy that information into OSM. I know that postcodes (but not addresses) from Royal Mail are OK, but don't know about Bristol's Pinpoint map. It looks like Bristol Council do have a lot of open datasets, but I cannot see one relating to addresses.

If you do not have permission, there other sources available online which are allowed to be used e.g. out-of copyright OS maps. Although an on-the-ground survey is always best if you can!

Happy mapping,
Jez