Doesn't have to be "public" access, if you are going to put it back into commercial use where it's open to all of your members, yes the restrooms will have to be ADA compliant.
Depending upon size and occupancy, you may be able to get by with a single uni-sex restroom.
Key things about ADA restrooms:
Large enough entry door for wheel chair, 36".
Room size adequate to turn wheel chair around in, typically 7' x 8' for a one holer.
Toilet and sink properly positioned and sized to meet ADA dimensions.
ADA grab bars at the toilet.
Tissue and towel dispensers properly positioned to meet ADA.
ADA accessible sign on door.
You may also need to have suitably marked, sized and located ADA parking spot(s).
Ramped access into the building for a wheel chair.
If in doubt, get with the local building inspector.