I'm driving on the freeway doing about 80km/h.

As soon as i speed up to 90km/h (i would go as far to say as exactly) my traction control kicks in.

This means i can rev all i like, put speed wont increase and the TCL light (and function) wont shut off until i drop below 90 again ? (I ended up turning it off and it let me go home in peace)

I did what every Magna owner does when something smells fishy (disconnect battery) and i haven't been able to recreate it since.

The only thing i have done in the last couple of days is change my steering wheel over from standard to the Ralliart one ? It also worked after i installed it and didn't have the TCL problems til the next day !

Should i be worried and book it in ?

It's probably nothing. If it hasn't happened again, I wouldn't worry about it.

It could have been a plug that's vibrated loose, or the ECU reading inputs and deciding that you're spinning the wheels instead of actually driving.