You can get the partition name from the subobject_name column of the all/user/dba_objects view. The object id for the partition is retrieved by the supplied procedure DBMS_MVIEW.PMARKER().

For example ...
Code:
Select
   ao.subobject_name,
   mt.my_column
from
   all_objects ao,
   my_table mt
where
   ao.object_id = DBMS_MVIEW.PMARKER(mt.rowid)
/