As noted by Narkissos, the New Testament does not quote Isaiah 9:6 at all in reference to Jesus.
Perhaps this was because the NT writers used the Greek Septuagint (LXX) extensively, and those words do not occur in the LXX at Isaiah 9:6.
However, the LXX calls the child here only "angel [or, messenger] of great counsel." So, if the NT writers had used Isaiah 9:6, it could only have been to say that Jesus was an angel.
Which, in fact, is what later theologians ("church fathers") of the 2nd century did: they called Jesus an angel and used Isaiah 9:6 (LXX) as their proof text.