Down the road from the fledgling Domino Sugar factory development site on the Williamsburg waterfront, another large-scale residential complex is having better luck in getting off the ground. The Department of City Planning has approved a rezoning proposal for the three-building, 801-unit complex that developers Abraham and Isack Rosenberg dubbed Rose Plaza on the River, in a 7-5 vote that allows the plan to proceed. It will now move on to the City Council for final approval, as part of the city’s public review process. A vote from the council is expected by early May. But the success of Rose Plaza could be a good sign for the developers of Domino Sugar, who were dealt an overwhelming rejection from Community Board 1 last night. Rose Plaza, which offers relatively little affordable housing — just 160 units — has been largely unpopular with the community throughout its public review process as well and was vetoed by Community Board 1 in December.