i believe that the text in matthew also was intended by Jesus to understand that he wanted each believer to be "fully immersed" (which is what the words for baptism mean) into the person of God the Father, into God the son, and into God the Holy Ghost. Jesus was instructing us to be sure not to leave any part of the godhead out of what we bring people into when we go out and spread the good news.
in acts, they were dealing with folks who had at least acknowledged God the father and so they went on to show that in order to receive God the holy ghost, one first had to be fully immersed in God the son, but it was not intended to be a "formula" only a matter of spiritual protocol. there is even some question as to whether or not all of these passages in acts refer to water baptism. when we read the 16th verse of acts 8 especially, this seems to be speaking of the fact that the believers in question were folks who had been immersed into christ, but not into the holy ghost, a situation which they proceeded to correct.
