During the Fourth Coalition against Napoleon Bonaparte, he participated in Gebhard Leberecht von Blücher's retreat to Lübeck, where he was taken prisoner.

Released after giving his word of honor, Bonin studied at the gymnasium in the garrison town of Prenzlau.

Bonin was successively promoted to Hauptmann in 1817, Major of the Alexanderregiment in 1829, Oberst in 1842, and Commanding Officer of the 16th Infantry Brigade in 1848.

After the armistice of Malmö, Bonin was named commanding officer of the army of the united duchies of Schleswig and Holstein, which he reorganized and strengthened during the winter of 1848–49.

"[3] Albrecht von Roon wanted to merge the Landwehr militia into the professional line army; Bonin, a disciple of the Napoleonic reformer Hermann von Boyen, favored the Landwehr and thought that Roon's plan would "separate the army from the country".

Influenced by Bonin's rival, Edwin von Manteuffel, William hand-picked a special military commission led by Roon to draft a reform bill in September 1859.

Furious that the Ministry of War was bypassed by William's actions, Bonin criticized the proposed reforms and pointed out the infeasibility of its budget.