Oracle Database Discussions

I created a partitioned table:
CREATE TABLE test
(
SITEID VARCHAR2(8) NOT NULL ENABLE
)
tablespace MAXIMO
partition by LIST(siteid)
(
partition west_coast values ('CA1'),
partition ocd values ('OCDRA'),
partition jom values ('JOM'),
partition rar values ('PSGARA'),
partition site_null values (NULL),
partition site_unknown values (DEFAULT)
)
;
But when I go to user_tables,
Select table_name, tablespace_name from user_tables where table = ‘TEST’;
I get table_name but tablespace_name is NULL.
I know table is made of partitions and tablespace_name can be different for each partition,
But is there anyway to populate tablespace_name for table TEST.

I have a third party application, I want to do spartitiong on some large tables but somehow bendor’s code is looking at user_tables and stops working because tablespace_name is NULL.
I was under the impression that under the covers one can partition table (just like adding indexes) and
Third party application will remain working without problem.
Any ideas will be appreciated.