The Shach (Yoreh Deah 166:1) brings from the Maharshal (Bava Kama 9:11): It’s forbidden for the lender to benefit from the borrower in matters which are known to the public, such as using the borrows slave, or staying in his property. However, the lender may borrow items in private, if the borrower would have lent them even before the loan took place. However, it’s forbidden for the borrower to honour him with a mitzvah such as calling him up to the Torah, or to buy for him gelilah, even if the lender knows that without the loan, he would have been honoured with this. Since such a thing is public, it is comparable to lending him a slave or property which is forbidden, unless it is known to everyone that it is being done unrelated to the loan.
The Maharshal (Yam Shel Shlomah) concludes: “One who has Yiras Shomayim should be very careful with these things, especially if he wants to wake up by techiyas hameisim”.
From the Maharshal it seems that even if the borrower doesn’t buy the aliyah, rather he is the shul gabbah and is in charge of who gets called up, it’s still forbidden, unless it’s known to all that he would have anyway received the aliyah.
[By gelilah the Maharshal mentions buying, however, by the aliyah he doesn’t, therefore, it seems that even without paying it’s a problem. However, see the Chochmas Adam (Klal 131:16) who understands the Maharshal that there is only a problem of giving the lender an aliyah if the borrower pays for it. See also the Bris Yehudah (Ikrei Dinim, Perek 10, He’orah 104) who takes on that if the borrower is a gabbah he may honor the lender with an aliyah - especially as the aliyas don’t belong to the gabbah – however, from the Maharshal it doesn’t seem like this.]
