Per Marriott Rewards, arrival gifts/amenities are for Platinum Elite members. If a particular property gave you an arrival gift/amenity, it was done so at that property's own discretion and is not required under Marriott Rewards
The amenities are as follows at Marriott proper in Baltimore:
Your choice of:
a) 500 bonus mr points
A) 2 beers, 1/2 magnum of white or red wine
B) mixed nuts,cheese and fruit plate with choice of crackers.
May change based on availability
HOPE this helps!