I think you have the bias in the wrong context. I constantly see similar comments about anti muslim bias in the media. Whenever there is a terrorist attack in Europe we get similar coverage to the New Zealans attack, but attacks in Africa or Asia get no coverage. One example is March 2004. The attacks in Madrid had saturation news coverage. The attacks at Ashura in Iraq, where 178 people were killed a weel before was hardly mentioned. I think media bias is more in favour of what they think their readers and viewers are interested in.

When any religious or ethnic group is attacked in developing countries, it is rare for the western media to report it. It's not restricted to Christians.