Jupiter in 11th House synastry relationships are based on friendship and cooperation in humanitarian, religious, educational, charitable, scientific-intellectual, cultural, and political spheres of life. With its social connections and status, as well as the diplomatic abilities, the “Jupiterian” personality helps the Eleventh House individual realize the conceived while the latter helps the “Jupiterian” one to express themselves more effectively in the surrounding social environment.
In a negative scenario, the partners begin to show hypocritical behavior and become unreliable, allowing themselves to make empty and ill-considered promises.
from F. Sakoyan, L. Ecker
Jupiter in 11th House Synastry Explained
If you find yourself in an informal group with a Mars in 11th House synastry, he can make a very strong impression on you as you suspect him of extraordinary nobility, the ability to perform miracles, or something of the kind. Indeed, through friendship with you (or joint participation in group activities without clear goals) can make this partner show generosity and open-mindedness toward you; but if his Jupiter is not developed, the partner’s arrogance and vanity can show, and you will react very sharply, considering them destructive both for your friendships and the interest of the group.
In general, Jupiter in Eleventh House synastry is a wonderful aspect for a budding relationship if the partner manages to resist the temptation to assert herself at your expense: then she will seem to you a wonderful find, a rare gift of fate, such a brilliant comrade that you can be proud of the mere fact of your friendship. In reality, however, this friendship, if it does take place, will bring happiness and good luck to your Jupiter in 11th House partner while putting you through a series of unforeseen hardships. But if your friendship endures such a test, then you will receive magnificent fruits as the partnership will significantly expand your opportunities for group work the directions of which will show the position of the Eleventh House in your natal chart, in particular, your planets in it and their aspects.
from A. Podvodny