FLT CREW OF B757 ON VISUAL BRIDGE APCH TO RWY 28R AT SFO IS SURPRISED TO FIND THEMSELVES CLOSELY ALIGNED WITH ANOTHER B757 ON A VISUAL APCH TO THE PARALLEL RWY; RWY 28L. DECLINE TO COMPLY WITH TCASII RA DURING ENCOUNTER.

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WE WERE FLYING THE FMS BRIDGE VISUAL FOR RWY 28R WITH A B757 ON THE VISUAL FOR RWY 28L. WHILE ESTABLISHED ON THE PROPER LOC AND GS WITH THE RWY IN SIGHT; WE RECEIVED A TCASII CLB RA. WE HESITATED TO CLB SINCE THE TFC WAS BEHIND AND LIKELY ABOVE OUR ALT. THE CLB RA WAS QUICKLY REPLACED WITH A 'CLR OF CONFLICT' AURAL. ACR Y ASKED US TO VERIFY THAT WE WERE LINED UP WITH RWY 28R; WHICH WE VERIFIED. BOTH ACFT LANDED UNEVENTFULLY; HOWEVER; THERE WAS NO NEED TO HAVE SUCH TIGHT SPACING -- ESPECIALLY AT NIGHT. I BELIEVE NORCAL APCH SHOULD PROVIDE AT LEAST 1 MI STAGGER BTWN ACFT ON THESE CLOSE VISUALS. NORMALLY THEY DIRECT ONE ACFT TO NOT PASS THE OTHER; BUT THEY DID NOT DO THAT ON THIS OCCASION. BOTH ACFT HAD ACKNOWLEDGED THE OTHER IN SIGHT AND APCH TOLD US TO MAINTAIN 210 KIAS UNTIL FURTHER ADVISED. I DON'T KNOW IF THEY HAD BEEN ASSIGNED A SPD. WHEN WE WERE JUST OUTSIDE SAMUL INTXN; APCH SIMULTANEOUSLY SWITCHED BOTH ACFT TO THE SFO TWR. OUR GND SPD APPEARED TO BE GREATER THAN THEIRS INITIALLY AS WE WERE JUST FORWARD OF THEIR POS WHEN WE JOINED THE RWY 28R LOC. OUR PROCS FOR THE SFO VISUAL APCHS ALLOW US TO SELECT THE TA ONLY POS ON THE TCASII WHICH I WILL LIKELY DO IN THE FUTURE TO AVOID THE CONFUSION WE FELT WITH AN ACFT BEHIND AND ABOVE AND A CLB RA. THE REAL ANSWER THOUGH IS TO HAVE APCH PROVIDE MORE STAGGER BTWN ACFT AND TO COMMAND ONE OF THE ACFT NOT TO PASS THE OTHER.