They probably wouldn't ask two Bolshevik questions, but there may be a Bolshevik question with either a power struggle question or a foreign policy question that ranges from 1917 to 1941. I'd learn both, just in case.
Errr. They always ask a Bolshevik and a Stalin question.
The Bolshevik question may ask: War Communism, NEP, Brest-Litovsk, social and political reforms within the party and everything that's under the Bolshevik consolidation of power in the syllabus. They wouldn't interrelate the Power struggle which is under Stalin's rise to power, which could be asked in the second question. However, the Bolshevik question could be either on Foreign policy, or it could be generic.