Does XA Grants Needed for 11.2.0.1 RAC?

Hi,

I have 11.2.0.1 RAC database running on AIX with Java application with WAS and have XA enabled datasource.Does the below grants still needed to be given?Can you please let me know What exact privileges are needed and also,what you be the impact of setting  " _clusterwide_global_transactions=false"?

grant select on sys.dba_pending_transactions to public;

grant select on sys.pending_trans$ to public;

grant select on sys.dba_2pc_pending to public;

grant execute on sys.dbms_system to public;

Thanks