I don't think throw-over panniers are a problem on the Tenere as the exhaust is covered and not too hot to touch (I asume that you have the standard exhaust). However before you take my word for it, try getting your bike up to full temp and see how hot the exhaust is.
I'm looking at getting some Cameron Barker waterproof panniers very soon. I'm not sure if you'd need any pannier supports for them, I'm hoping that they'll be ok without.