Manager Sam Allardyce signed N'Gotty from French outfit Marseille in 2001 in a deal worth £450,000.
Allardyce said, "Bruno has been the catalyst in what we have achieved. He has made an immense contribution."
"He hardly misses a game and has become a bit of an old stager, who uses his vast experience.
"We didn't pay much for him either, as Marseille were going through a difficult time financially."
The former France international lasted just one year with Marseille before switching to Bolton and insists he has never looked back.
N'Gotty added: "Now I can prove I'm a better player than I was at Marseille.
"But while the European campaign is good, it is more important for us to do well in the league and FA Cup."
Meanwhile, Wanderers skipper Kevin Nolan is being linked with a £10million move to local rivals Manchester United, while El-Hadji Diouf could be out for a while with a groin problem.