Thank you for posting your question in the Support Community! Traffic shaping is per-interface. In your example, egress traffic from interface vlan 666 (going out toward the WAN carrier) will be limited to 10 Mbps throughput. Egress traffic from other interfaces will not be affected by traffic shaping on interface vlan 666, though it is possible to apply traffic shaping to them as well, if desired.
Traffic shaping is a great feature as implemented in AOS. An ADTRAN router will attempt to gracefully delay traffic instead of simply dropping packets which exceed the rate limit. Check out Configuring QoS in AOS for additional info and config examples. Depending on the type of units you manage, Configuring Enhanced Ethernet Quality of Service (EEQoS) in AOS may also be a useful way to go--especially when using sub-interfaces and VLANs.