Check out Law 77 for a complete scoring table. "For making any partscore - 50".
This new player was obviously confused. He/she may have been thinking of: 1) The bonus for making a redoubled contract was increased from 50 to 100 pts - that was in 1987, a lot more than 4 years ago. or 2) In some variations of Chicago (four-deal), an unfulfilled partscore is worth 100 pts.
Neither of these have anything to do with the ACBL.
Assuming that you are talking about Duplicate bridge then the part score bonus is 50 points, and has been for a very long time! The ACBL do not have the right to change it, since it is decided by the World Bridge Federation Laws Committee.
I can guess why your friend is confused. Some time ago the bonus for making a redoubled contract was increased from 50 to 100 points - perhaps this is what he is thinking of? This was longer than four years ago though.
--- David Stevenson <email@example.com> Liverpool, England, UK http://blakjak.com/lws_menu.htm
Is it possible the poster is asking about rubber bridge. According to the 1993 Rubber Bridge Laws the bonus for a remaining partscore is 100 points. It used to be 50 points but I don't know when it changed.