Hi Ray,
Thanks for your interest in Syncfusion Products.
Yes you can use Tooltips in GridTreeControl when flying over an item. We have created a sample based on this. Please find the sample in the following Location.
Sample:
http://www.syncfusion.com/uploads/redirect.aspx?&team=support&file=GTC_Tooltips-427716271.zipPlease let us know if you have any queries.
Regards,
Manikandan J R.