First let's set up the situation .
You may have mentioned it previously but, my short term memory is old
What is your current recording chain ? And how are you recording ? are you using one mic simultaneously ? two mics simultaneously ?
since you mention "bleed" I assume simultaneously so the first obvious answer is record the guitar first then while listening to the guitar overdub the vocal.
But understand bleed may not actually be the issue ( there are thousands of recording done that have bleed but sound good) there are a number of possible variables involved.
First for the optimum in replies ...You can just do a simple signal flow sentence like (here is my current signal flow)
Simultaneous style
Guitar > pair of AEA N22's > > OMNI interface > computer/DAW
Vocal > ADK 251> MP2A mic pre > OMNI > computer DAW
Overdub
Guitar > pair of AEA N22's > MP2A > OMNI > computer DAW
Vocal > ADK 251 MP2A > MP2A > OMNI > computer DAW