I can't alter my original post sadly (HK's solution did not in fact fix the problem after some testing), so I might as well update with my own circumstances.
I have a small set of locations set up in Mavericks to let me switch between the following configs:
Network 1 Thunderbolt - static IP
Network 1 Wifi - static IP
Network 2 Thunderbolt- static IP
Network 2 Wifi- static IP
Automatic (just connect to anything, wired or wireless, DHCP)
Generally I want to use either Network 1 or 2 through Thunderbolt for 95% ~ of my time so that's what I've been testing. Wifi appears to be pretty solid, no problems with that reconnecting after sleep in any tests.
When connected to AC power: Thunderbolt NIC will wake from sleep and bring the link up OK.
This is my best 'workaround' for the issue - just leave the macbook connected to mains power constantly and try not to think about the long term ill-effects it does to the battery conditioning 😟 (Also it ties up one of the limited plug sockets around here)
When running on battery: Thunderbolt NIC will *not* bring the link up after waking from sleep. Sometimes changing the network location to something else, then back to the one I was previously working will cause the link to come back up. Sometimes it doesn't however, and I am left to physically disconnect and reconnect the thunderbolt adapter.