Edit: Oops, didn’t notice you have a 4 cylinder engine, that means the turbo 2.0 L right? In that case it appears to be an interference design, and does use a timing belt. VW dealership would have the recommended maintenance intervals specs, probably around 80-100 K to change to the belt and tensioner.
Prior info, may be bogus for your car …
Are you sure this vehicle uses a timing belt? From what I can see, the Jetta Sedan 2.5L (BGP) engine at least uses a timing chain. If this applies to your car; i.e. it uses a timing chain, they aren’t usually replaced as a scheduled maintenance item. To maintain the timing chain it’s important to keep the oil change interval to VW’s spec, keep it topped off at all times between changes as required, and use the proper oil.
Suggest to make sure and phone up a VW dealer and ask them if your car uses a timing chain or a timing belt. from what I can tell the 2.5L is an interference design, so if it uses a timing belt it could damage the valves if it snapped. Some manufacturers are moving away from recommended change-out intervals, in part b/c it means the car needs this servicing and that downgrades it in the cost-to-own ratings. It seems like the pro’s here – of which I’m not one, just a DIY’er – the say around 60-80 K and 7 years, whichever comes first, is when to change the timing belt. Again, this is something the VW dealership would know for your make/model/year.