The denim bandeau would be gorgeous, but that might limit wearability. The colorfull travel bandeau would also be great. Or the heart coin purse in pomme, which would complement the red interior of the ebene damier. It's a gorgeous bag. Congratulations.
I like it with no bandeau... the gold plate on the front gives it some visual interest, I think a bandeau would look like too much is going on... to me the bandeaus look good on more simple bags like speedies, neverfulls, etc.
i think that the berkeley has enough hardware to stand alone, but if you really want to put a bandeau on it....i would actually go with an Hermes twilly instead.... alot more variety with twillys than bandeaus
plus, twillys are smaller and not overbearing like the bandeaus are