I'm not seeing the conflict of interest on the part of the prosecutor here. Conflicts of interest are generally those things that might cause the attorney to be less than zealous in the representation of the client or that would result in the use of confidential information about one client against another. Neither of those situations are present here. There might be other ethical problems here, however, in particular the prosecutor's potential abuse of his office to further the civil claim.
I said there "could be" a conflict of interest.
A lot of (probably important) facts are missing from Wonder's story, including how and why he became involved with CPS, and what reason or reasons the prosecutor has for pursuing felony charges against Wonder (other than a criminal conviction apparently will benefit the prosecutor's clients in a civil case).
Wonder might want to try talking to his public defender again, first, to see if he can get a better understanding of the criminal charges and the plea bargain that was offered.
There appear to be enough questions raised by the prosecutor's handling of both the criminal case and the civil case that a personal review by a different attorney in Wonder's area seems a good idea.