The following is only a brief summation as you have variety of options to get from Samana to Bavaro. YES. BUT.
Via air domestic flight from Samana to Punta Cana airport one way price is about US$ 99. AND THE SAMANA AIRPORT IS NOT SO GREAT. TWO PLANES CRASHED IN LAST MONTH.
Via bus, one carrier from Samana to Santo Domingo then another carrier express Santo Domingo to Bavaro. Note: there are different variations of this route. Cost is very cheap. THIS IS GOOD FOR BACK PACKERS, PEACE CORPS VOLUNTEERS AND VERY YOUNG AND FLEXIBLE FOLKS.
Via taxi - usually priced max for five persons US$300. I SUGGEST THIS TO ANY TOURIST WHO CAN AFFORD IT.
Via passenger ferry from Samana to Sabana del Mar, surface transport (taxi-bus, bus will involve interchanges at various locations ) to Bavaro. NEVER DONE IT. AND I AM NOT EAGER AFTER LEARNING HOW THE SURVIVOR SHOW WAS FILMING THERE AND TRIED TO SHIP A GARBAGE TRUCK ON THE FERRY. THE TRUCK FELL OFF, I HEAR. I AM NOT SO TRUSTING OF THE OPERATORS SINCE I GOT THIS STORY FROM MANY LOCALS...
Note: Nisibon is not what PJT would consider as part of the Bavaro area. It is a village area about 2 to 2.5 hours distant from Bavaro/Punta Cana by surface transport, a very pleasant scenic ride.
Is your destination actually Nisibon? If so, you will have additional transport logistics to contend with. The forum may be able to assist you with more detailed information if you desire.
Regards,
PJT