Dwayne is correct.
The key thing is you need to select the armature, shift select the mesh and then jump into weight paint mode.
You will then be able to select the bones with YOUR selection method.
Because I’m Right Click Select, I don’t have to change anything. I just right click.
But if you are Left Click Select, you will need to press a whole bunch of modifier keys to tell Blender to select instead of paint.
This is one of the benefits of separating the action from selection in the old school Right Click Select
(how are things down there by the way? I can’t quite tell because I’m up on this high horse.)
