Confused how to wait for Partitioner


I am using the partitioner package to separate my collections.
I have a problem when changing the group of a user.
On the client side I call a method on the server. Within this method the group of the user is cleared and then set to another value. On success the client is redirected by FlowRouter to the dashboard. The problem here is, that one react component needs the new value of the users group set before by the server method. Now this value is undefined and is updated after the component was rendered.
I know from the docs of partitioner, that I have to change my subscriptions to resubscribe them after the group of a user changed. But how can I do this in this case?

Hope anybody can help
Best, Daniel