Don't boil pine tea!
The main benefit of pine tea is the vitamin C, which is destroyed around 200deg F.
To make pine tea, bring your water to a boil and then take it off the heat. Wait until the boil has stopped but while the water is still scalding hot and put in the needles. At this point, while the water is above 180deg but below 200deg, the outer carbohydrate strings are dissolved allowing the needles nutrients to be released into the water without the temperature being high enough to reduce the nutritional benefits of the tea.
Pine tea isn't the best tasting thing out there but there are some things that can be done to help. Pine needles contain tannins, that's right I said tannins. If you have even burned pine tea, reaching 215f or higher, you will notice a dry aftertaste similar to cheap red wines. If you get that aftertaste, all nutritional value of the tea has been destroyed. There are no usable sugars in the needles, at least not that will be released into the tea. That means the tea's flavor will benefit from a sweetener. Anything from table sugar and honey (more modern) to birch sap and berries (field expedient but still yummy imo).