I have not tried this, but would be quite interested to see what the results are. Bonding on its own, I would think would have originated with ethernet. It would work well in the case of using an ethernet card with a WiFi card, or using 2 ethernet cards.
But bonding between 2 different WiFi cards can be difficult. You would need to make sure that they are on different channels and the signals don't interfere with each other. Even if they are on different channels, there is no guarantee that there would be no physical interference (since physically they are so close on the node). You are optimizing for intranet though -- which would mean that you have a single router (with a single Wifi card). So it can only operate on a single channel.
A better way to solve this is to root cause the poor reception in the WiFi network itself. Are your nodes too far from the router? Is there very high EM interference around (e.g. microwave ovens)? What WiFi card are you using? (would switching to a better WiFi card help? would switching to a better router help?)
All that said, using 2 WiFi cards could work, but more in the scenario where they are on different frequencies and connecting to different routers to boost internet speed. But that too would be experimenting.