Afraid not (I made that mistake before - so did the stupid dealer)..
The 1.4tsi which is available in the golf gt has a supercharger and turbo charger (and in the A3, and the scirocco). But in the leon it has no supercharger, just the turbo.... Which to me sounds wierd (as you'd think that's what TSI stood for), but apparently not..
It's the same engine but without the supercharger. VW also do a golf, without the supercharger but it's 122bhp, the leon is 125 - the twincharged golf is 170bhp.
I'm half expecting that the next FR release will have the twincharged engine..