Link Aggregation for Video Editing (?)

Skip below to TL;DR if you don't care about the background.

Hi all, looking for some help to understand what's going on with my link aggregation. I'm the de facto IT guy at a small public access TV station (with my background more in video and audio engineering).

For those who aren't familiar, public access is basically the library for video: anyone can come in and check out cameras/equipment, use the studio, and/or edit in our community editing room - all free of charge. For that community editing room, patrons are currently logging into network accounts and storing archived files on our NAS. As of now, all the editing needs to be done locally on a SAN connected device (we use 2TB LaCie Rugged Thunderbolt bus powered drives). When someone comes into edit, they check out "their drive", which is shared among 4-6 people.

To avoid the scheduling nightmare of people sharing these drives, we've decided to take the step towards folks storing their edit on the NAS. The speed theoretically works, but rendering is a bit slow.

TL;DR

I'm looking to create a link aggregation from each computer to the NAS using the physical ethernet port and a thunderbolt ethernet adaptor. For some reason, I'm getting the same speed whether I'm using either of these connections or both of these connections (roughly 500/500Mbps for read/write). Why does creating a link aggregation not double my speed?

Late 2013 iMac running macOS 10.13

• Gigabit Ethernet port

• Thunderbolt Gigabit Ethernet adaptor

• ^ bonded to theoretically create 2G connection

Late 2012 Mac Mini Server running macOS 10.12.6

• 10G fiber connection to switch

• Thunderbolt connection to RAID