PPTP over Bonded Wireless Link?

I am currently in the process of switching part of our network over from a Bridged/WDS network to a Routed network.
I currently at one location use a wireless bonded connection for greater thoughput, and fail-over. Across the bonded link I have various PPPoE connections all working fine on the bridged/WDS design. However, as soon as I go to a routed system, the PPPoE tunnels will of course not function. I am testing a PPTP tunnel setup but am having all kinds of weird issues. IP connectivity across the bonded link appears fine, and the PPTP connection appears to work, BUT… and here is the issue

when testing the PPTP connection with both interfaces of the bond operating speed is a dismal 2 Mbps, and funcuates considerbly. As soon as I disable one of the links in the bond (forces all traffic across one link), speed of the PPTP connection goes to 9.6 Mbps. Any ideas?

You got bonding working without any issues?
Please post the full config.

SMA

1st RB532
WLAN1 - bridge mode, static WDS
WLAN2 - bridge mode, static WDS
Bonding interface - includes both static WDS entries, balance rr, arp link monitoring
Bridge - includes ether1, and bonding interface

2nd RB532
WLAN1 - WDS slave mode, static WDS
WLAN2 - WDS slave mode, static WDS
Bonding interface - includes both static WDS entries, balance rr, arp link monitoring
Bridge - includes ether1, and bonding interface