The place is really nice; separate from the house and accessible through the garage via your own door. Very clean and fantastically equipped, you could feasibly cook every meal there and have no issues. The place was very hot in the current heatwave, however, and there is no Aircon (but a very powerful fan is provided). Additionally we had to deal with a lot of mosquitos which meant that keeping the windows open wasn't really an option. So if, like me, you're the type that mosquitos seem to love, then beware (although this applies to most of France, I believe). The garden is also lovely, although bear in mind that the pool is only accessible when Marie-Anne (the host) is home (it's only accessible through the main house). She's very quick to reply to messages so it's easy to tell if she's in or not, and you can liaise with her in advance to check her schedule, but this is not the place for a lazy poolside holiday. It's more suited to those who'd like a mixture of both exploring the city and relaxing by the pool.
In terms of location, the place is about a 30-40 minutes from the city centre by public transport (usually 1 or 2 buses/trams, depending on where exactly you're going - Google maps is helpful with this), or about 20 minutes by bike. Bordeaux has a great city bike scheme called V3 which is really clever, and has a station nearby the apartment and loads in the city. It's quite cheap, but just know that it takes a €200 deposit which apparently takes 3-4 days to be returned to you - if you're using a travel card with limited funds on then this could be an issue!
Ultimately we thoroughly enjoyed the stay and would recommend it - I'm sure you'll have enjoy it so long as you're informed about the things I've mentioned above.