Tourist,
Without knowing the facts of the incidents you talk about (RN ships seeing B2s), it's not possible to use them as evidence of the utility, or otherwise, of stealth. The whole premise of stealth is that you cannot (with current technology) build a klingon-cloaked aircraft that is totally invisible. Rather, you shape your aircraft to deflect the incident radar into very restricted arcs, none of which are in the head sector. With appropriate planning you can then reach your intended target and kill it before its radars see you.
So the RN spouting gumf about being able to see B2s is as deceptive as the infamous 'moving Australia' incident.
Regards,
Single Seat, Single Engine, The Only Way To Fly