He said both things to both men at different times. The Tahoe shooting brought out the Master Manipulator in Michael. First he practically reduced Tom to tears by telling hom "You're my brother." Then he practically brings Pentangeli to his knees by yelling at him, "...in my house,...in my bedrooom.. ," then asks Pentangeli to help him take his revenge. "Michael, anything..." (Frankie practically in tears). That's when Michael asks him to put his head in the lion's mouth by meeting with the Rosatps. Then he bullshits Roth by callng him "Mister Roth," then telling him he's a "great man," then asking his permission to whack Pentangeli. Great stuff, Mike! You'd have made a good Presidential candidate.