Multisite - will they interact?

Hi,

I am (finally) setting up a networked site.

domain.com
subdomain.domain.com
subdomain.domain.com

The subdomains are specific 'niche' sites for the overall domain. I know if blog posts are created then the posts are shown in the activity stream. I know your Q&A plugin does not go to the activity stream.

However, can a question added to a subdomain plugin area show up in the domain.com area?

For example

Someone goes to subdomain.domain.com and asks / answers a question. Can that be reflected at the top level?

I hope that is clear.