I would not advise attaching a harness to the RSTB, both because of it's location and how it's usually secured (usually not welded in). You need a bar behind the seats running between the B-pillars if you want a bar, though there are other less permanent ways to install a harness correctly.
98.5 SVT
91 Escort GT (almost sold)
96 ATX Zetec (i brake to watch you swerve)
FS: SVT rear sway bar
WTB: Very cheap beater
CEG Dragon Run - October 13-15