In RHEL 4, if you had only one bond, you would define your bonding mode in the /etc/modprobe.conf. Note that this configuration only lets you create one bonding device. If you wanted two bonds with different bonding options you had to do something similar to what you see below.
Instead of this in your modprobe.conf…
alias bond0 bonding
options bond0 miimon=100 mode=1
alias bond1 bonding
options bond1 miimon=100 mode=1
You would have this…
install bond0 /sbin/modprobe bonding -o bond0 miimon=100 mode=1
install bond1 /sbin/modprobe bonding -o bond1 miimon=100 mode=0
If you didn't and you tried to define both bond configs in your modprobe, you will only have one module loaded called bonding and bond1 will get the options of bond0. Not exactly what you want.
Note that you may need to modify your modprobe.com and add the following line… max_bonds=2.
In RHEL 5 you actually define the bonding options in your bond config file (/etc/sysconfig/network-scripts/ifcfg-bondo for example), with the BONDING_OPTS variable: BONDING_OPTS="mode=1 miimon=100". You will need to do something similar in both ifcfg-bond* files.