i dont think theres a way to prevent the spot light from affecting the glow.

but what you can do is, reduce the brightness of the glow so when the lights make contact, it won't be super bright.

to do this visit the shaderGlow shader in hypershade. in the attribute editor bump down the "threshold" value in the global shaderglow node.

Another option is to turn of the auto exposure in this node, this will re-evaluate the glow intensity level per frame so when the lights it, the glow intensity doesn't keep rising as more lights hit it so it stays at a contant level.

but a better alternative is to create a single light then instance it onto particles, write an expression so the lights pop on and off randomly, now particle instancing won't allow this but you can download a mel script from highend 3d that will allow it, its called "jms_pr"