From Shaykh Gibril: His S.ûfi Affiliation With the Qâdirî T.arîqa According to the S.ûfî Ibn `Abd al-Hâdî in his Bad' al `Ilqa bi Labs al Khirqa, Ibn Taymiyya also declared himself a follower of several S.ûfî orders, among them the Qâdirî path of Shaykh `Abd al-Qâdir al-Gîlânî on whose book Futûh. al-Ghayb he wrote a hundred-page partial commentary covering only five of the seventy-eight sermons of the book. In al-Mas'alat al-Tabrîziyya Ibn Taymiyya declares: "Labistu al khirqa al-mubâraka li al Shaykh `Abd al-Qâdir wa baynî wa baynahu ithnân - I wore the blessed S.ûfî cloak of `Abd al-Qâdir, there being between him and me two shaykhs." http://www.livingislam.org/n/itay_e.html
I have heard a speech by Mufakkir-e-Islam Syed Abdul Qadir Jilani where he discussed this waqiya and mentions other things about ibn taymiyya's respect/relations for Huzoor Ghous Paak - some things that really surprised me. if it is online I will try to give the link, it is very imformative.
listen to the first 8 mins or so of this video http://haqchaaryaar.net/Videos/Volume61.htm the sayyid says that ibn taymiyyah used to send nazr and niyaz to baghdad every month for ghawth al-a'dham radiyAllahu ta'ala anhu.