When a jet engine is running, it's generally immune to any liquid in the incoming air as the liquid would have been evaporated in the compressor. However, when the engine is being cleaned for carbon deposits, cleaning solution mist is injected is fed to the inlet, and the water would have the chance of entering the compressor bleed. Is there any special design in the bleed path to keep the water out, or the water simply couldn't get past the labyrinthine seals around the bearings?
To keep dirt out, bearings with exposed faces have rotary seals on them. Those seals will also keep water out, as long as the bearing is not rotating when wetted and not completely immersed. If immersed for days or weeks, even well-sealed bearings will eventually allow water in.
Water is kept out because the oil is supplied to the bearings at a higher pressure than the surrounding air, so the oil mist is blowing away the air, not the other way around.