In this paper we model virtual buying cooperatives (VBC) with grammars of regulated rewriting and show that, if VBC relevant information is distributed over several successive VBC processes and must, in a later stage, be synchronised and co-ordinated, the formal grammar needs to be very powerful with respect to mode of derivation and thus generative capacity. In particular, we show how to model the supplier phase, invitation phase, and declaration phase of a VBC with random permitting context grammars and the VBC reservation phase with random context grammars under a special kind of leftmost derivation. If we use random permitting context grammars for all processes, we can only model a VBC formation during which information is introduced and processed locally and successively rather than being spread over different VBC processes.