Unfortunately, Panda3D's bam2egg doesn't seem to be compatible with the 3DS's BAM models. It gives me an error like:
:loader(error): en001a.bam is not a valid BAM file.
Unable to read.
The only effect it seems to have on these files is creating a 0 byte .EGG file.
I tried this with several different BAM files from Persona Q and Etrian Odyssey IV, but none of what I tried was recognized. Not even the bam-info program could read them. (Gave the same error)