Hmm... your link doesn't work for me (goes to an error page). According to my order history I got "15X6 5-105 ET39 ST NEW (Qty:1)" meaning 39 mm offset.
If my understanding of offset is right, the wheel with 35 mm offset would stick out 4 mm further from the car. I feel like that small difference is unlikely to make much of an impact, especially in a spare tire application. But then again I'm far from being a wheel & tire expert.