WHAT HAPPENS TO YOUR CAR IF THE BEARINGS IB YOUR ALTERNATOR GO?

No,

If your electrical system is not charging, the car will not get spark and die.

Sputtering is usually due to fuel system.

Spend $75 and let a mechanic tell you what is wrong.

Now go drink a beer and relax.

To answer your question, when the alternator bearings go the alternator begins to make strange noises and eventually the armature could freeze up if you don't replace it. Somewhere between the start of the noise and the freeze up it will stop charging because the spinning the armature will starting rubbing against the internal parts and do permanent damage. Its highly unlikely that your alternator is responsible for the puttering and stalling. We have no idea what vehicle we're talking about because you didn't tell us but generally speaking puttering and stalling are going to be related to either fuel or ignition issues not alternators.

I suggest that your new battery is now flat, or nearly flat, this will certainly cause the puttering and stalling.

But, there could also meany be other things wrong, what, I can not tell form here.

No, so get things checked BEFORE you replace them.