Well, there are many with, and many without, spines. I would not use Bauhinia variegata though, because even if the flowers are lovey (both the white one and the purple one) it has the unpleasant habit of a Cercis, let's say, to keep the hanging seedpods for ages, and they are not very good looking. What you really need is a summer flowering one, do you? In this case Bauhinia forficata (it does require some, but not a lot of water), with white spidery flowers that are very elegant, would be you choice. B. blakeana is also wonderful, seldom without gflowers, it only sheds its leaves briefly in June and then puts them back and starts again flowering, but it does need summer irrigation.
The best one for mediterranean gardens is really the yellow flowered Bauhinia tomentosa - which stands drought, but is smaller, it is really a shrub.