I have installed genisoimage version 9:1.1.11-2, this correctly reads the .genisoimagerc file. I have also installed 9:1.1.11-2 of wodim and cdrkit-doc.
However I do not use these to generate any El Torito boot image. I hope that this helps. Genisoimage is very useful, however, it would be even better if it were to correctly read the .genisoimagerc file, as stated in the man pages with best regards from Richard Betham