Hi,
I configure bonding interfaces a bit differently.
I put only this line into /etc/modprobe.conf :
alias bond0 bonding
And use this in /etc/sysconfig/network-scripts/ifcfg-bondX :
DEVICE=bond0 BOOTPROTO=none IPADDR=192.168.100.1 NETMASK=255.255.0.0 ONBOOT=yes BONDING_OPTS="miimon=100 mode=1 primary=eth0"
I've got setup running like this in mode 1 (failover) and in mode 4 (LACP). Unfortunately I don't have any systems with more then 1 bond and I don't have anything spare to set this up. But you can try your setup using this way to configure it, maybe that helps.
Regards, Tim