(breakfast around 7.30am at home but later will be given to him to childcare)
9am - morning tea
11.30am - lunch
3am - afternoon tea
(late pick up around 6pm)
I consider the "morning tea" and "afternoon tea" to be snack times, and would consider them as being times when they are having a small snack and water (or milk in a cup) rather than a full meal or bottle. From the routine there are 2 main meals and two snacks...unless you missed a meal out?
You don't mention "dinner" (or whatever you call your main evening meal) which toddlers often like to have around 4.30 or 5pm. As you don't pick up until 6pm this is the earliest time he can eat again, is it a long journey home? If so you might give a packed dinner in the car before you set off (I wouldn't expect a LO this age to eat whilst a parent drives, bit of a risk), or if it is a short journey you could feed an evening meal as soon as you get home although you are going to be really pushed for time so I'd still suggest a packed lunch type meal which you can prepare the night before and just leave in the fridge ready to serve cold on arrival home.
At this age mine had dinner earlier (4.30pm ish) and then a "supper" around 6pm which replaced his BT milk, so he was getting WU milk (full amount taken by straw rather than bottle), breakfast, snack, lunch, snack, dinner, supper with small amount of milk (no BT bottle).
I'd give the bottle/straw/cup of milk at WU and then breakfast, and if needed one at BT too.
He shouldn't need a night feed at all at this age. But small tummies mean they need lots of food opportunities in the day.