You need to have two matrix objects in the same matrix sheet. The matrix object that contains the surface data should be active.
You also can add error bars to the existing Color Map Surface graph, by using Plot Details dialog.
Activate the matrix object that contains the surface data.
From the menu, choose Plot > 3D : 3D Colormap Surface with Error Bar.
Click the 3D Color Map Surface with Error Bar button on the 3D and Contour Graphs toolbar.
(Installed to the Origin program folder).