98 R1100RT front susp. maint. question??

The owners book says to "grease the lowerfront suspension strut pivot". What is that? Is it the lower shock bolt? Is it the ball joint on the lower arm? Or something different?

It's the lower shock bolt I believe. A light coat of grease on the shank of the bolt aids in alleviating an annoying squeek.
Just keep the grease off of the threads

Grease both the bolt shank and the outside of the bushing, I even grease the areas where the bushing contacts the U-bracket on the Telelever arm. This is also a good time to inspect the U-bracket connection to the Telelever arm. Any rust evident in this area must be inspected carefully and cleaned up right away. I have heard of some instances where the U-bracket breaks free of the arm. I recall it is "pinned" in place so as long as the arm cannot over-extend down it does remain in place. But, uncertain feel in the front end may be caused by a loose U-bracket.

For those who are over-diligent at cleaning their bikes, especially if you use any form of high-velocity cleaning water/spray, be aware you could be forcing water under the U-bracket. There should be a good bead of sealant around the U-bracket to the arm.