My best souvenir of Bordeaux was a lovely reproduction watercolor of an iconic Bordeaux streetscape. The artist, Jean-Luc Helin, sold it to me at his store, which offers many other streetscapes, water views, landscapes and views of vineyards, in different sizes and at very reasonable prices, as reproductions of his original works. The store is open 2-7pm, Tues.-Sat.
Aquarelles de Bordeaux, at 32 Rue Bouffard, is on a four block pedestrianized street known for collectibles. This same back street is where the Museum of Decorative Arts/Musee des Arts Decoratifs is at #39, and the excellent cafe Cote Cour is in its walled forecourt. (I cannot recommend Cafe Bouffard on the corner.) Out on the main drag (rue Nancel-Penard, which ends in Place Gambetta), there is an official city sign that is an arrow reading Les Antiquaries de la Rue Bouffard. The Fine Arts Museum/Musee des Beaux Arts is also nearby.