Due to project constraints, I'm using PetaLinux 2014.4 and Zedboard for development along with the FMCOMMS2 card. I've booted the board with the supplied SD card, and after updating the SD everything worked, so the setup is sound.
I followed http://wiki.analog.com/resources/tools-software/linux-drivers/iio-transceiver/ad9361 and after a little effort was able to get the kernel modules for the cf_axi_adc, ad9361, cf_axi_dds, and others all loaded. A normal modprobe command loaded these successfully without any additional work. I'm using the same working bit file that I used in the previous step, when running with the pre-supplied uimage file and BIN file downloaded here - http://swdownloads.analog.com/cse/2014_R2-2015_04_24.img.xz - for the zynq-zed-adv7511-ad9361-fmcomms2-3 version.
However, after booting and loading the kernel modules, looking into /sys/bus/iio/devices/ all I see is the iio:device0 corresponding to the Xilinx XADC, which I can see from cat'ing the name attribute. What needs to happen so that devices 1-4 become visible?