Pulis' side opened the scoring when Gareth McAuley headed home from a corner in the first-half but they were eventually pegged back through Michael Dawson.
West Brom continued to plug away but they were forced to settle for a point ahead of their next game against Watford.
Pulis snapped up Nyom for £3m from the Hornets in the summer and he has started the club's last eight league games.
His performance on Saturday received plenty of praise and Pulis admits he has been a key signing.
He told Sky Sports: "Allan has played well all season for us. He's a smashing lad and gets on with his job.
"He's one of the last to come off the training pitch and works very, very hard. He's been a very, very good signing for the football club."