We did it some years ago. I donot remember how much we paid for a cab, but check your rate before boarding a cab. The white cabs at the cruise-terminal are more expensive then the yellow ones along the highway.
Around Vta Adventures there are no restaurants, but you will find some in the area of Nuevo vallarta.
On the way back you might pay a different price for a cab, since you leave from a different state.
(Pto. Vallarta is in Jalisco, Nuevo Vallarta is Nayarit).