I know that Sabre's Virtually There and Amadeus' Check My Trip will both show seat allocations where the information exists in their systems. I have no experience with the Galileo site.

But if the airline does it in its internal system and does not queue the infomration back to the GDS, then these sites won't show it. QF sometimes allocate seats for me which show in Amadeus (which hosts QF) but the information does not queue back into Sabre which my travel agent books in.