pg restore - where is the schema?
You didn't restore the dump. Your pg_restore invocation output the contents of the dump to standard output. To restore the dump into a database, you have to add the -d option:
pg_restore -U postgres -h db -d databasename ambari.dump

The second attempt seems to have succeeded. You probably don't see the tables because they are not on your search_path. Try \dt *.*.