Mr Mises and his Von never did me any harm with wing structures.
But back to the post, is your structure plain skin, or does it contain stiffening members?
If your structure can be considered as a membrane (i.e it is so thin that it may be considered to carry no bending), then its an easy job of the membrane tension added to the direct tension.
If there is only a limited curvature then you could just consider it as a flat plate, the effect of the curvature will stiffen the panel.
Is tension loading due to wing bending really the design critical case?? If i extrapolate, if its in tension due to wing bending and pressure then its a flight case, so the panel must be on the underside of the wing. The pressure and flight WB cases will probably be less than landing (ground) cases which will if im correct give a high compression load onto the panel and give rise to potential buckling.