If one makes an early shabbos, one may ask a Jew who has not yet accepted shabbos to do melacha for him (based on this answer and its sources). I would assume that, all the moreso, one could benefit from a melacha done by a Jew who wasn't asked. Other than the time concern (how close to shabbos) there seem to be no limitations
But on the second day of Yom Tov in Israel, concerning whether a disapora Jew can ask an Israeli to do melacha for him, Halachipedia reports
Yalkut Yosef (Kitzur S”A 496:27; Chazon Ovadyah (Yom Tov pg 138)) permits a non-Israeli to ask an Israeli to do melacha for him on Yom Tov Sheni. However, Sh”t Igrot Moshe 3:73 and Sh"t Shema Shlomo 1:9 forbid. Rav Elyashiv (in Kuntres Teshuvot siman 54) writes that the only concern is Memotzi Chefsecha which is permissible for a dvar mitzvah.
This doesn't address whether one can benefit from action not done expressly for him or her, but even to the question of asking directly, some opinions absolutely forbid and one imposes limitations.
Why would there be any difference between the application of the law of "asking a Jew to do what you cannot do" in the two cases?