No. West Berlin was in an odd legal position within the context of the Cold War and German division, but it was a de facto enclave of the FRG. The city was subject to Basic Law, albeit its own municipal city council had to pass their own version of it. The city's residents were FRG citizens and West Berlin's constitution asserted it was part of the FRG (whether it was a separate Land or some as as yet to be determined entity was a topic of contention though). The city could send non-voting delegates to the Bundestag and most of its municipal administration such as the post office fell under the responsibility of the respective agencies in Bonn. West Berlin's mayors like Brandt were able to use the city's visibility as a front line for German division and the Cold War to catapult into the national visibility, but at no point did the city's leaders maintain it was an independent entity. West Berlin's exact legal status was an anomalous, but its leadership hitched its star to Bonn and the FRG.