Greetings and welcome.
According to Max BMW's excellent online fiche (a US dealer and website), they are not the same. The '99-04 LTs have one part number, the 05-09 LTs have yet another part number, and ALL years of the RSs have the same part number for the throttle body assembly, but it is not the same as that of either year range of LTs.
What is the difference? That I do not know.
Check out Kirk Johnson's excellent Youtube channel and possibly contact him for how the throttle bodies may differ. He is a trusted and true asset to the BMW maintenance community, and knows LTs.
Gentle reminder: Know the year and model you are looking for and asking about. Good luck.