knowing face applied texture ?
 

how to retrieve which texture is applied to the a poligonal face?

like listAttr texturename pCube1.f[2] ?

it is possible?

Select the face and make a quick select set out of it then assign a material to it.
You can also just go to the hypershade and select the material

another way is to select the face, then in the hypershade> graph materials on selected objects