... I do not there there is way, not with the WorldEnvironment node. The WorldEnvironment node is for applying effects across the entire game, hence why it is affecting all of the sprites rather than just a single node.
You can get something similar to a glow effect though by using Sprite nodes and setting the Material to CanvasMaterial and setting the draw mode (I think that is the property is called ) to Add. Then the bright parts of the Sprite will be added on top of the existing colors, rather than mixing with it, which can create a "glow" like effect. You may need to make a "Glow" sprite, which is just a sprite where the pixels you want to glow are white and the rest is black, for best results (then you can use the Sprite's modulate to get different colors)
