According to the rules of the road, bicycle drivers have as much right to the roadway as other vehicle drivers do...no more, no less. It is not, however, legal for them to ride side by side and take up the whole road. Although it's not a problem where there is little traffic and they move aside for other traffic. They should be in single file except in cities where they are moving with traffic. They should also be obeying every traffic rule. It seems many bike rider pick and choose which rules to follow.
Motor cycles can be double on the road, but no more than double. Since they are moving with traffic, they have no obligation to move aside and let cars pass.