I stumbled upon a wonderful little store on C/ Mallorca 241 in Barcelona the other day called Lokavore. They stock all Catalan products, including a decent amount of produce grown from within Barcelona proper.
I've been looking everywhere for Casa Mariol vermouth, which is made only with Macabeu grapes. The woman who owns the shop hadn't heard of it, but she nonetheless ordering it for me and had it for me a couple of days later. I think they might even stock it now.
The store is only a couple of months old. The couple who runs it is very warm and generous and clearly passionate about Catalonian culinary products. If you're in Barcelona and looking for anything local to try or take home as a gift, I would highly recommend stopping here. Some evenings they do wine tastings with regional producers, so it's worth a stop in to see what's going on.