Don't allow that wind pollinated thing to stop you. Do find out whether olives are worked by bees for pollen and nectar. Soybeans and cotton are both important crops in both your country as well as mine. Honeybees work both these crops even though soybeans and cotton do not need or benefit from honeybee pollination.
It may be that a lush ground coven like Dutch clover is planted in olive groves and your bees may live the life of Reilly in olive groves even though the olives them selves are a complete bust.
Pick a pack nick lunch and spend a day lounging in an olive grove to check out the incidental bee forage for yourself.