This might make your life simpler (or possibly more worrying, considering how long you may have been doing this wrong): You're supposed to brush before meals. It's technically harmful to brush immediately after, as it removes acid softened enamel. Brushing removes plaque, not food, so you actually want to brush the plaque off before eating, as it immediately produces acid when the food hits it, so most of the damage is done to your teeth well before you brush... the softened enamel of your teeth away, increasing the damage.

So, there you go, you simply get him to brush at the start of his bedtime routine, then story, then bottle, then sleep.

Sources: The Dental Hygenist magazine and the NHS guidance on teeth cleaning.

This might make your life simpler (or possibly more worrying, considering how long you may have been doing this wrong): You're supposed to brush before meals. It's technically harmful to brush immediately after, as it removes acid softened enamel. 

Brushing removes plaque, not food, so you actually want to brush the plaque off before eating, as it immediately produces acid when the food hits it, so most of the damage is done to your teeth well before you brush... the softened enamel of your teeth away, increasing the damage.

So, there you go, you simply get him to brush at the start of his bedtime routine, then story, then bottle, then sleep.

Sources: The Dental Hygenist magazine and the NHS guidance on teeth cleaning.