We are using antibiotic, such as chloramphenicol in Sabouraud dextrose agar and also in Pal sunflower seed medium ,which was developed by us in 1980 as a selective medium for the rapid isolation and presumptive identification of Cryptococcus neformans from clinical and environmental materials.
You should be able to add antibiotics to any formulation of agar plates. Just note that you should add after autoclaving (since the autoclaving will inactivate many antibiotics).