Can Grapevine pattern of communication be effective in managing a change within an organization?

No, as the recipient will understand the communication according to his/her background, and (s)he may send a different message than the one intended. In addition to that, having a set of conversations down or up through the ladder, we may lose the message. If organisation is too complex, and has too many roles, we can back this method with general audience newsletters, posters, etc.. to make sure we send the message accurately and correctly.

Grapevine Communication is fine for informal flow of Information. To manage change Grapevine communication is not enough. It may be used for small organization . Also to get feedback for a change Grapevine Communication may be used.