Stunning place and area, my favourite of the French regions.
Road:
Ridden loads, but it’s flat’ish. Head up to St Emilion and east towards Mouliets et Vilemartin for the bumps, then head back south Targon and Pondensac, then West to Sauternes. Mixed road, lanes and vineyard small single lanes. Sauternes area my fave, sort of rolling soft landscape with epic views all around.
MTB:
Little in the way of bumps, few gravel tracks open to public (vineyard owned, gated) but some open if you head over West towards the forest/brushlands south west of Bordeaux heading towards Arcachon.
You don’t say where abouts in Aquitaine you will be, but North of the Garonne in Cognac it’s more hilly, and road riding is just as lovely.