It looks like the "JBL" system you mention is really the Panasonic/JBL system in the non-nav TCH. It has the 6-disc changer. The nav TCH has a Denso/JBL system with a 4-disc changer. It appears that either can control/tune XM IF you add the receiver:
"Use of satellite radio requires XM tuner and service. Contact your Toyota dealer for details." (From TCH Owner's Manual) I think you're going to have to mount an XM receiver someplace conspicuous. Maybe your Toyota dealer could confirm. If I find the pic online again, I'll post a link.