Two plate can be bonded in ANSYS using interface element or contact element..this element is used to simulate two plate contact point and there is a common node used to define the plates at the boundary between two plates. Here, at the contact point i.e. at the point where two plates are bonded together, there is two unknown i.e. normal displacement - normal to the contact surface and shear displacement i.e. shear displacement b/w two plates..The bonded interface behaviour can be simulated using normal and shear stiffness..i suggest you to read ANSYS manual for further understanding on this aspects..ok all the best..
I have never used Ansys, but this sounds like a solution sequence where you 1) prestress one plate, then 2) connect the plates using contact elements, e.g. by moving them into contact at a very low velocity and possibly, also using some damper elements in between to slow down the contact.
Question is a bit vague and needs to be more clear on boundary conditions (BCs). I'm agree with Dr. Fredo regarding the sequential method, however, if BCs allows, I rather to perform the analysis in one simulation for minimizing numerical error.