They're both called Business Contact Manager, from the same vendor,
but are otherwise unrelated--they don't integrate.

VPN is the only way to get full access to BCM offsite. For security
reasons BCM will only work with authenticated network connections and
that requires more handshaking between machines than "just internet".
Virtual Private Networks provide the plumbing to make the internet
connection appear like Local Area Networks to applications like Sql
Server and BCM.

There is one exception or alternative. It requires less networking
software, but more manual work. Some users exchange BCM files. They
export the items that have been changed since the last sync, email the
BCM files, and import with the merge changes option.

Note that shared users only share the same email and Outlook calendar
and tasks, if they are using the same Exchange server with Outlook.
Otherwise, BCM will track those items in a contact's history, but BCM
will only store some of the fields, not the full Outlook items.