Please note the following commands:
\list or \l: list all databases
\dt: list all tables in the current databaseYou will never see tables in other databases, these tables aren't visible. You have to connect to the correct database to see its tables (and other objects).
To switch databases:
\connect database_name or \c database_name
http://www.postgresql.org/docs/current/interactive/app-psql.html