Why does this make you assume that you have a bearing issue? You did not describe any clicks or clunks.
What you did describe was vibration upon applying the brakes that ceases upon firm pressure. That seems to suggest an uneven surface and potentially a broken brake clip or worn guide.
You need to check the brakes first.
'09 PSM G8 GT - OPG Intake, DOD-Delete w/ Stage 1C 218/229 .600 Lift 117.5LSA, Kooks 1 7/8 Mids, Solo Axle-Back w/ X-Pipe, SuperPro Bushings (Front and Rear). BMR Sway Bars (Red)
"If you want to criticize someone else's work, be sure that your own is in order first."