The Reinforced Carapace talent only increased the shield on allies shielded by the Network Carapace talent when both were picked. The host of the symbiote would receive an untalented value of shields.
Thanks for the report! Did this issue occur in Try Me Mode? I am not seeing this interaction in a normal match; however, there appears to be an issue with Carapace shield in Try Me Mode that we are aware of.
As a note, Networked Carapace applies untalented shields, so Reinforced Carapace wont work on nearby allies. But it appears you are saying the opposite is occurring, correct?
If you continue to encounter this issue, could you please send in a replay to our Heroes Bug Attachment Inbox.