If it were the bearing, it could only get worse and not better.
A slightly loose alternator belt will give a sound like a bearing just as a thought.
If you can't reproduce the sound and the belts are tight , I'd not worry about it.
'95 Ranger 5.0 GT40X Tri-y GT40 Intake S-Trim Snow Stage 2 Lowered Baer Racing Brakes Viper Spec Tremec w/Hurst shifter Custom Interior Dakota Digital Dash Corbeau Toplines OZ Racing AM/FM/Mp3/CD/DVD/TV.
2014 GTIG 5.0 Vert Base. Sil Carb Fiber dash. Bama Race Tune. Gibson axle backs. STEEDA Springs KONI STR.T Adj. Panhard. Dynamatted. Audiocontrol LC8i Amps and Sub! Leather OEM seats. Custom Badging.