I am not sure to quite understand your problem. A wire is (in Open CasCade) just a set of connected edges which are supported by curves. So I don't think you want to "triangulate" curves.
When you provide a planar wire to BRepBuilderAPI_MakeFace, it can deduce easily a plane which can then be used to build the face. SO in this case you don't need to provide a surface to BRepBuilderAPI_MakeFace. In case of a non-planar wire it is not obvious to deduce the supporting surface. So in this case you have to provide a surface ( a bezier, bspline,cylinder, sphere, etc) to BRepBuilderAPI_MakeFace.