@barry, if you on that route, why not use a parser, and ONLY replace the parts (read the adaptors), that you want to override...
you would probably need to translate your config to an iface command of some sort... (im not 100% sure how that works)... but it would still allow (read ... enable) you to change the other interfaces for example the ones not being bridged...
at some point zentyal obviously should change the way that it 'detects' your network devices...
so that when you bond eth0 + eth1 both of them are 'disabled' from being managed, but instead you get an new virtual device that you can manage simular to any other device, including bonded, virtuals, tunnels etc. all of these shuld be treated as regular nic's.