User wants to be able to send reimbursable and non-reimbursable bills to QuickBooks Online while retaining their labels. But when they are sent, they are all tagged as reimbursable.
When you use the bulk action, Sync Settings > Send To, all vendor bills are sent as reimbursable by default. If you want to separately send reimbursable expenses only, go to the Time & Expense Reviewer and click 'Details' for the expense entry you want to send. On the Edit Expense Entry screen, click Actions > Send To > QuickBooks.