Backup Tablespaces that are in different FS

Hello,

I am using pg_basebackup to backup my postgresql database cluster. I have continuous archiving enabled. My tablespaces are on seperate file systems and are outside the data directory .However,there are only symbolic links in pg_tblspc that point to these filesystems.How do I include the tablespace filesystems to be backed up in pg_basebackup? or Does backing up data directory itself will behind the scenes backup tablespace file systems?
I am planning to test inplace recovery (meaning backup/recover on the same machine) by backuing up data directory , dropping a database and then recovering to the same data directory.Is this possible?