No, you should contact the scheduler BEFORE the shop, and ask them if it's okay to bring 2 people instead of one. And if they say yes, clarify any questions about how to handle the check, and if necessary, also reimbursement.
Often, the +1 guidelines are not just about the reimbursement. I've done some restaurant shops that stipulate that you either can (or MUST) bring one guest only, and others that don't care how many you bring, but state that reimbursement is up to 'x' amount. In cases where they're firm about not bringing more than one guest, the concern is usually about distraction.
Don't run the risk of a rejected shop before you even do it.