A bit disappointing, but the 9 Plus doesn't come with any pouch, sleeve, bag whatsoever.
If you shell out $32-$40, you can get the Samsung Slim Pouch for ATIV Book 7/9 13", available in several colors:
]AA-BS8N13B - Black/:m]
]AA-BS8N13W - White/:m]
]AA-BS8N13L - Blue/:m]
]AA-BS8N13R - Red/:m][/list:u]
Who knows of any other(/better?) alternatives?