They are fairly incompatible with humans and the cannot inhabit populated areas. Therefore although wolves have found the means to boost their numbers given the smaller human persecution and their own capacity overcome adverse conditions, bears have not been able to keep their population up. The decline of the Spanish bear in the last decades has been, I think, definitive. Also the fact that roads are built and that their habitat is changed affects bears tremendously. Wolves can cope with all these situations with much greater ease.
Bears have the highest possible grade of protection.
European directives dictate that bear habitat must also be strictly protected. Bears are considered a priority conservation species. There are only two or three other species in Spain which have the same degree of legal protection, for example the Iberian lynx or the Monk seal. As well as the hunting of bears being strictly forbidden, the areas they inhabit all have some degree of protection in the form of natural parks or similar bodies. The European Union has assigned large sums of money to bear conservation.