I was able to get it working:

1) uninstall TaggTool Server,
2) Install the 32 bit JRE
3) reinstall TaggTool server (64bit) WITH the JRE

I ran into the same problem during install. While it was in the starting service loop, I popped into the folder I installed to and manually ran Taggtool 5.exe and got a dialog telling me Java couldn't be found. Selected the correct install path and then waited for it to retry and it completed install.

The service just immediately exits after starting though.