In Cryptonomicon, there are three people who escape from the Golgotha gold store in the 1940s, Goto Dengo, Wing and Bong, in the chapter called "Deluge". Goto Dengo and Wing play prominent parts in the rest of the story, but Bong is not mentioned again.
There is a driver called Bong Bong Gad, mentioned in the modern thread of the story, who drives Shaftoe and Randy into the jungle. I'm not sure if he is related though.
Just curious is anyone has any thoughts or theories about Bong.
He was killed by robbers on the road while returning home.
In 1945, Root meets Goto Dengo and lets Goto know that he (Root) knows about Golgotha:
They stroll silently for a while. Root's feet kick the hem of his robe out with each step. "I know other things," he continues. "South of here, a man brought diamonds to a priest. This man said he had attacked a traveler on the road, and taken from him a small fortune in diamonds. The victim died of his injuries. The murderer gave the diamonds to the Church as penance."
"Was the victim Filipino or Chinese?" asks Goto Dengo.
Enoch Root stares at him coolly. "A Chinese man knows of this?"
By implication, if Root counters by asking if a Chinese man knows about Golgotha, then it must have been the Filipino (Bong) who was killed. (And, as you say, Bong is not mentioned again.)
(quote is from chapter "R.I.P.", page 860 in the hardcover)
