I think he wanted somebody to back him up in the upcoming political fight, though whether that counts as being a minion is an open question. I never quite figured out what Tony mean in that Civil War issue (was it The Confession? I'm blanking now) when he said that Peter surprised him. Did he surprise him by switching sides, or by ever siding with Tony in the first place? Tony originally opposed the SHRA, if I remember rightly, so did he originally expect Peter to help him fight it? It's all very confusing.