Comment 1 for bug 63988

I also ran into this. Your assessment seems correct.

As a temporary stop gap, you can configure the following in network/interfaces:

iface bond0 inet dhcp
  pre-up modprobe bonding
  pre-up ifconfig bond0 down || exit 0
  pre-up ifenslave -d bond0 eth0 || exit 0
  pre-up ifenslave -d bond0 eth1 || exit 0
  pre-up ifconfig bond0 up
  pre-up ifenslave bond0 eth0 eth1
  post-down ifconfig bond0 down

This is basically just doing the work that enslave's ifup/down plugins should do, on your own.