I've found that some batiks bleed horribly and others, not at all. The fabrics I buy (good brand names) have never bled but I was gifted with a lovely bunch from the island of Bali.
I'm SO glad that I tested one piece by soaking in hot water. With mine, the bleeding was almost instant and it bled a lot! I machine washed following directions on the bottle of Retayne and just last night finished ironing them!
Normally I do not pre-wash fabrics but this time with the intense colors I did.