Abstract: Transformation optics is mainly enabled by metamaterials with varying indices and anisotropies. For two dimensional propagation, the twopolarizations are usually decoupled and manipulated separately. By using anisotropic media with non-trivial principal axes, we show how polarizations can be coupled and controlled within a framework using field transformation, in addition to the conventional coordinate transformation approach. For example, we can design a device to achieve complete cross-polarization conversion between TE and TM waves. We can mimic a perfect magnetic conductor of arbitrary shape. We can also obtain additional impedance control, by using more complex materials, when a transformation optical device is matched to an object. In a related context of metasurfaces consisting of a mono-layer of spatially varying metamaterial atoms, we will discuss how geometric phase elements constructed from anisotropic metamaterial atoms can be used to manipulate spin-orbit interaction on structured light with both orbital angular momentum (OAM) and spin angular momentum. We will show spin-induced effect on the OAM, as a manifestation of optical spin Hall effect and orbital rotation.