Hello and welcome. 
As for your first question:
Under the Imperial period, "Germany" itself did not issue any commemorative coins; rather, the various member-states of the Empire issued commemorative coins: Prussia, Saxony, etc. Otto von Bismarck was a Prussian politician, so it would be on a Prussian coin, if any, that you would find him. However, there were no such Prussian coins, either. The only Prussian commemoratives to feature people other than the Kaiser and his immediate family were the 100th anniversary of the Defeat of Napoleon coins, which depict various soldiers standing around the Prussian king on horseback.
Neither did the Weimar Republic, Third Reich, West Germany, East Germany nor Reunified Germany ever strike coins in his honour, as far as I can tell. However, he has featured on some non-German coins: In the 1970s, Paraguay issued a series of "influential people of the world" coins, for want of a better term; the Bismarck coins came out in 1974, silver 150 guaranies and gold 1500, 3000 and 4500 guaranies. Here's the 1500 guaranies in the NGC database.

As for your first question:
Under the Imperial period, "Germany" itself did not issue any commemorative coins; rather, the various member-states of the Empire issued commemorative coins: Prussia, Saxony, etc. Otto von Bismarck was a Prussian politician, so it would be on a Prussian coin, if any, that you would find him. However, there were no such Prussian coins, either. The only Prussian commemoratives to feature people other than the Kaiser and his immediate family were the 100th anniversary of the Defeat of Napoleon coins, which depict various soldiers standing around the Prussian king on horseback.
Neither did the Weimar Republic, Third Reich, West Germany, East Germany nor Reunified Germany ever strike coins in his honour, as far as I can tell. However, he has featured on some non-German coins: In the 1970s, Paraguay issued a series of "influential people of the world" coins, for want of a better term; the Bismarck coins came out in 1974, silver 150 guaranies and gold 1500, 3000 and 4500 guaranies. Here's the 1500 guaranies in the NGC database.
Don't say "infinitely" when you mean "very"; otherwise, you'll have no word left when you want to talk about something really infinite. - C. S. Lewis