Scene Asset Bundle - LoadLevelAdditive and OnLevelWasLoaded

This question has 2 parts.

First :

Is there a way to get the index of a scene loaded from an assetBundle ? At runtime ?

Second :

Is the function OnLevelWasLoaded called when you use the LoadLevelAdditive ?

Now, the reason I want to know this is because i'm using a script which deals with scene changes, it also handles showing and hiding the loading screen when needed. As of now, I was just calling the "Show" method (for the loading screen) before loading a scene, and then, in that scene, I had a script that would "Hide" it from the Start. Let's face it, this isn't... well encapsulated. And it's kind of a pain to need a script in each scene to call the loading screen off.

I recently discovered the OnLevelWasLoaded method, which would actually achieve what I want. Problem is, some of these scenes are bundled. (Not in the project settings), and I have no way of telling which index they are. Hence the First question.

After thinking for a bit, I thought "Well, I don't actually need to know which scene is loaded, I just need to dismiss the screen when a scene is loaded, Any".... well, ends up that's not exactly true. There's some scenes I am loading additively (is that a word ?) And I don't necessarily want the "Hide" function to be called at those times - Well, sure, right now it's not doing much, but it might eventually do. Hence the Second question

If it's not fired, then I could work with this workaround.

Thank you for your time, hope I was clear enough.

EDIT:

I just thought about something, Is it possible to get the name instead of the index ? and then get the index with the name ?

EDIT 2 :

I found part of an answer to that last question Here

Says you can Check names with assetBundle.contains, but not really get the name without knowing it first.