I had a friend who was previously working under company sponsorship until her husband landed a job in a good company and became eligible to sponsor her.
What happened was she had to go back to her home country for a few months while they transfer her visa.The mandoop of her husband's company sort of pulled some strings to lift the ban in her visa.Her previous employer didnt give her release actually..
If your company can do that for your wife in case that her employer did not grant her a release then you can sponsor her.But if they did give her the NOC then you can easily transfer her visa under your sponsorship.