Hello, I'm not sure I fully understand the desired setup. Would you be able to provide a brief network diagram showing the existing and desired setups, including VLANs?
It sounds like you want to change from a single ethernet PIPE to a multiple ethernet 'PIPE', but do you want the same on both ends of the link? Does the data need to remain segregated across the RF link?
It is most likely doable, but would need some additional information to confirm a setup. Some of these other links may also help:
http://community.cambiumnetworks.com/t5/Licensed-Microwave/LAG-options-for-PTP-820S/m-p/72222#M559