Analysis
The April Theses, presented by Lenin upon his return to Russia in April 1917, explicitly called for the transfer of power to the soviets (workers' councils). The slogan 'All power to the Soviets!' became a central demand of the Bolsheviks, reflecting Lenin's push for a socialist revolution. This is well-documented in historical records and Lenin's own writings.
Background
The April Theses were a series of directives issued by Lenin to the Bolshevik Party, outlining his vision for Russia's transition to socialism. The soviets were grassroots organizations of workers, soldiers, and peasants that emerged during the 1917 February Revolution. Lenin saw them as the vehicle for proletarian dictatorship.
Verdict summary
Lenin did advocate for 'All power to the Soviets!' in his April Theses of 1917.