Is one allowed to benefit on Shabbat from an item that someone carried outside of the techum? For example, a non religious family member who lives 2 hours away drove to my house on Shabbat and brought me a bottle of wine. Am I allowed to open it on Shabbat? Does it make a difference if the person knows he is doing something wrong and brings it anyway?

Shalom, Thank you for your interesting question. The laws of benefiting from Shabbat desecration can be found in the Shulchan Aruch, Orach Haim, 318,1. The case you mention is a particularly interesting one, as the desecration did not change the item at all, as for example when someone cooked on Shabbat, when the food is changed by the forbidden labor of cooking. When the Shabbat desecration did not change the item (in your example the question is not just one of the Shabbat techum [boundary] but also of being driven in a car, and possibly going in and out of the eruv [that is carrying]), the matter is argued by the great early Rabbis. The Rashba and the Ritbah both hold that such desecration does not forbid using the item on Shabbat. But the Rambam (Shabbat 6,24) holds that if the desecration was maizid [on purpose] the item is forbidden for use on Shabbat, but if it was done by mistake [shogeg] one may use it on Shabbat. The Rosh is also of this opinion. The Shulchan Aruch (405,9) rules like the Rambam and the Rosh. However, many latter day Rabbis are lenient and permit the use of such items even on Shabbat itself in times of need, such as to perform a mitzvah (see Yalkut Yosef, 318, 68). In general, if you can avoid using the wine on Shabbat, that would be the best thing, as it is hard to believe that the guests are unaware that driving is forbidden on Shabbat. If your family situation is such that not using the wine will cause great trouble or strife, there is room to be lenient when the need arises. Blessings.