Do Stellar & Ripple organizations communicate/collaborate?
Or are they totally separate companies that do not work together?
Ripple and the Stellar Development Foundation are separate entities. They were both founded by Jed McCaleb. Ripple was founded as a private company in 2012. The SDF was formed some time after Jed left Ripple as a not-for-profit organisation. Whilst initially similar, the two payment protocols diverged significantly when Stellar was re-written. As far as I know, there are no partnerships between Stellar and Ripple.