In an attempt to locate my family coat of arms I came across "The Potgieter genealogy pages - http://www.geocites.com/Heartland/Park/7152/
" this is an excellent site possibly linking to the Potteiger's you mention. A short extract:
"In 1674 Harmen Jansz Potgieter, son of Herman Potgieter and Schwenne Lodden arrived in South Africa. Harmen was born in 1635 in Nordhorn, Wesfale, Germany. He moved to Amsterdam in 1670, where he married Isabella Frederiks of Amsterdam in 1672. Harmen and Isabella had three sons and four daughters in South Africa. Johannes Potgieter (23 Sept 1674) was the first Potgieter to be born on South African soil."
I know this is taking you to the other side of the world but having recently moved to Australia many Australians get my surname as Potteiger so possibly there is a connection. Many Dutch families located to South Africa and it is likely that there are links between the Pennsylvania Dutch and the South African Dutch.
Merry Christmas and all the best with finding the lost branch of your family tree.