I've three different accounts activated in SourceTree. Two different Bitbucket accounts and one GitHub account.
If I switch to the Remote tab in the SourceTree overview, I'll get all repos of my private Bitbucket account and of the GitHub account. I don't see the repos of the Bitbucket account of my company. I'm not an administrator, but I've rights to read and write. In the browser I've access to all the repos.
Fix for this issue is available in Sourcetree 4.2.2