Moderator, Marriott Bonvoy & FlyerTalk Evangelist
Join Date: Oct 2002
Location: McKinney, TX, USA
Programs: United Silver; AA Plat/2MM; Marriott LT Titanium; Hilton Gold
Posts: 11,727
When points are transferred, those points are deducted from the LT points of the original account and added to the LT points of the receiving account.
When you say "miles purchased" do you mean purchased points with cash directly from Marriott? Or something else? If purchasing points, I do believe that those points are added to your LT total as well.