Berlin would not have been bombed. There's a reason Dresden was firebombed instead of Berlin. The allies were trying to get to Berlin as much as the Soviets were, even after Yalta.
Patton wanted to take the war to Moscow, and it's a rather lucky break for the soviets that he was held back from what he wanted to do. Remember: Czechoslovakia could have been liberated by the allies three months before the Soviets got there. It was Yalta that kept that from happening, and it was Yalta that allowed the Soviets to storm Berlin.
In any scenario where a nuclear drop in Germany is even remotely possible, Berlin is not a target. And if it is, it is in preparation for a war with the USSR which, by 1945/46, would not have been feasible or doable. The trenches would have returned and shown their ugly faces in Poland and Ukraine. Russia had a million tractor factories that had all been turned into tank factories at this point. So imagine the same scenario where the Soviets throw more men at the enemy than the enemy has bullets, but turn it around into a scenario where they're throwing more tanks at the enemy than the enemy has tank shells and you have two things:
A war that cannot possibly continue and the USSR becoming utterly insolvent by 1960 and a collapse no later than 1970 (and that's being generous.)
Cooperation with the Soviets was paramount to winning the war in Europe, and Stalin wanted Berlin.
Berlin is NOT a target. At all.