I have a booklet on the "Land Records of Prince George's County, Maryland 1710-1717" by Elise Greenup Jourdan.
There is a listing for a John Tanehill(planter) and his wife Sarah (widow of Robert Bowen), selling land in P.G. Co., MD in 1710.The name in the same record is also spelled Tanyhill.
There are also quite a few listings in 1710 for a William Taneyhill, one mentioned that he was an attorney.All the records, except for one, were deeds that William witnessed.The one dated 16 Nov 1714 a 280 tract of land (Philips Trough) which he was selling.This was located on the west branch of the Eastern Branch of the Potomac.(I believe this was near the Anacosita River.)
There were no other listings in the index for people with this surname.I will check my other books if anyone is interested.