can you confirm that vocals are out of phase with both guitars individually? maybe its just one of the guitar mics? If you are 90 degrees out of phase there isn't much you can do, as nudging it will create either more phase issues or timing issues. you can try scooping some of the offending frequency out of the guitars but this is one of those get it right at the source things. I cant imagine that there is that much vocal bleed in a guitar close mic unless the guitar is very quiet and the vocal is very loud... Without eq, compression etc. is there still a phase issue, because you said you were happy with it when you hit record.