Well, the People's Temple and Applewhite didn't worship Christ.
Applewhite's Heaven's Gate was a "New Age" religion, he claimed to have arrived via UFO from another dimension (a "level above human") and would return via a secretive "Process", which was taught to cult members. These are not Christian beliefs or Christian doctrine. Applewhite's bunch had no more to do with Christianity than it did with the San Deigo Chargers or the Crew of the Titanic.
Jim Jones was similar. He started out as part of the Disciples of Christ, but by the end he was calling HIMSELF the new Messiah. Well Christianity teaches that Jesus and Jesus alone is the one and only Messiah. If you are telling people that Jim Jones is the Messiah, or Marshall Applewhite is the Messiah, you can't be Christian. The definiton of Christianity is that you accept that Jesus Christ is the Messiah... if you don't believe that Jesus is the Messiah then, (jinkeys Scooby!) you aren't a Christian.
So Christianity is not linked to Jim Jones or Marshall Applewhite because neither one of them had anything to do with Christianity. They both had their own little wierd relgions, and they wern't Christian.
Islam, on the other hand, has a lot to do with the bombings. The bombings are carried out by Muslims, who are following the Muslim Holy Book that teaches that if you die while on Jihad (killing the enemies of Islam) you go to heaven. So Islam is the motive of the bombing... and these guys leave behind videos saying they are doing this because they are Muslim, and then other Muslims all praise them and say how great they are. (Remember on 9-11 CNN had video of the Palestinians CELEBRATING in the streets? giving out cake and dancing?).
So while there isn't a link between Christianity and Jim Jones and Heaven's Gate, there is a pretty strong link between Islam and terrorist bombings.
That's why Islam is linked with the bombings, and the suicides aren't linked with Christianity.