Partition of tablespace
There are a few backup options for you.

A standard dump (pg_dump) will be restorable on another machine but you may want to create the tablespaces first before restoring.  Where the tablespaces are is not really a concern for the recovery.  Note you can also do pg_dump -Fc and this will allow you to select tables to restore at restore time.

Another option is to use pg_basebackup if you are on 9.1 or higher and this will rebuild your data directories over replication.  See http://www.postgresql.org/docs/9.1/static/app-pgbasebackup.html for more on this option.