Yes, you can connect multiple Recurly sites to the same QBO account.
Basically, you CAN sync Recurly Account 1 and Recurly Account 2 to QBO company A, but you CAN'T sync Recurly account 1 to QBO company A and QBO company B. You can only connect one Recurly account to one QBO account.
If you need to change the QBO account you are connected to, you’d first have to delete your existing QBO connection by contacting our Support team. Once this is deleted, you can login to your preferred QBO account and connect it to Recurly.