I was staying in Punta Cana.
Check with Bavaro Runners, they may offer transfers from La Romana area.
WELCOME TO :: FARALLON ZIP-LINES ADVENTURES
La Romana is about 1 1/2 from Punta Cana.
I know the ride from Punta Cana to the zip line was approx. 45 min to an hour.
Have fun!
Tracy