I would book through PenClub or Virtuoso (most PenClub agents are also Virtuoso mebers). Give the agent screenshots of the OTA rates, and ask the agent to request a rate match from Peninsula.

Your TA, working directly with his/her contacts at the hotel, will get you the best rate and value added benefits, including PenClub’s totally flexible arrival and departure times, which are far better than an ordinary late check out benefit. You simply arrive and leave exactly when you want to at any time of day or in the evening.

While the miles and rebate may be tempting at first glance, I think it would actually be a penny wise pound foolish decision to forgo the added value, particularly upgrades, that a good TA can get for you. The hotel would rather work with a good agent that has a relationship with their sales and reservations departments than have you just click on Expedia, costing them a large commission to the OTA that essentially does nothing for the hotel and adds no real value to you.

It would be better even to just book on Peninsula’s own website than use an OTA. However, a good agent will get you the best value, so that is what you should do. Do not focus on trivial differences in rate, focus on the big difference in value that you receive.