Partitions are a feature of B-Tree and Hash databases only. Per the documentation (http://download.oracle.com/docs/cd/E17076_02/html/programmer_reference/am_partition.html):
"Only the BTree and Hash access methods are supported for partitioned databases."
You can use Queue extents in order to break up the size of a Queue database. You can find documentation about managing Queue extents here: http://download.oracle.com/docs/cd/E17076_02/html/programmer_reference/rq_conf.html#am_conf_extentsize