The Winery is near the entrance to Alinor, and it’s easy to spot it if you follow the road into town from the north. It is the one with the blue rooftop tiles, and a large front yard where the busy workers are making wine.
The Skyshard that is overlooking the Oleander Coast Winery is behind this building. Although it is on a plateau, it is blocked by a large tree. Simply go behind this Winery, and you’ll be able to spot and collect it, acquiring that precious skill point part.