You each will receive a friend request from the Monria Fleet Manager, and after you accept it, you will be added to the Yamato guest list and sent an invite to the Yamato chat channel. Follow the instructions at the bottom of the first post in this thread in order to be able to see our forum Shoutbox. This is where we communicate with our Yamato passengers.
Also, make sure that you have all planets and space downloaded so there is no disruption during travels. Prior to logging into the game, click on the "Tools" link at the bottom right of your Client Loader and see what's checked and not checked.