Anisotropy in material works as in other renderers. You can set amount of anisotropy: more value will make reflection less rough in given direction. That direction is evaluated on UV coordinates or (if object has no UV) from global axis. It also can be modified by setting angle. Both of those settings can use a texture. Notice that angle value and value from texture will be summed. You should use gamma value 1.0 for those texture channels.
