My organization currently has many different divisions and business segments. For example, we have a commercial division that supports our residential and wholesale division. Most divisions have easy access to the other divisions via sharepoint.
We're currently hosting sharepoint 2013 on premise and it doesn't matter what their email address / domain is. We're opening up another company in Puerto Rico that would be fairly independent of the other divisions, but we will still need sharepoint access across all divisions.
Initially, I was going to create a new account and new tenant in office 365, mostly because we would like this company to have a separate GAL and as far as I'm aware, you can't separate GAL's by domain in office 365. However, at some point we may migrate our sharepoint to office 365.
I'm wondering what the integration would look like at that point across companies. For example, how easy would it be for the puerto rico division to access the commercial divisions sharepoint site, and vice versa? Could we link to the other tenants sharepoint site. Would they have to enter a different set of credentials? Ideally, we'd want it to be seameless where the commercial division would be able to log into sharepoint and see, residential site, commercial site, wholesale site, puerto rico site.
So for the sake of a cleaner GAL and separate management, I'd like to create the Puerto Rico site as a separate tenant, however not at the expense of more cumbersome sharepoint integration down the road.
Any advice would be greatly appreciated.