How to call a function on an instance

On my playerScript, when i press spacebar, the function “PlantBomb” is called. This instantiates the “bomb” prefab. I’d like to run a function of bombScript (the script of bomb), and pass it a variable, letting it know how long to wait before exploding. The only error i’m getting, is the line that has bombTimer on it. It’s bombTimer is red, like it doesn’t know what the function is. This function exists on the bombScript though. Any help?

public GameObject bomb;

void PlantBomb () {
var bombClone = (GameObject)Instantiate (bomb, transform.position, transform.rotation) as GameObject;
bombClone.GetComponent<bombScript>.bombTimer (5);

if (Input.GetKeyDown(KeyCode.Space))
	PlantBomb ();

If C# try this:

bombClone.GetComponent<bombScript>().bombTimer (5);