Personally I didn't bother with a set time at that age. Their timing will change vastly over the next year or more with weaning , sleep regressions, illnesses, nap developmentals, changes to your routine if they start nursery ect..
I would just do the routine from whenever baby would want or need their last bottle.
Also you don't need to bath them every night unless you really want to or they are dirty.
Mine is now 16 months and we bath every other night unless there is a reason to do an extra (food in hair ect)
I think it must have been from about 3 months I would do a vague routine but It wasn't until around 5 months when we had started a bit of solids that I did a proper routine and built it up.
Bedtime started at 10 and then gradullay got earlier, when we reached 14 months we finally got to head down at 7, so bed time routine starts at 6.
However all babies are different so you will knows yours just don't expect too much and don't tie yourself in knots if it doesn't go to plan for at least 12 months or more these little people chop and change and i found it easier to go with the flow and eventually it falls into place.
Something to bear in mind way down the line apparently there are 2 types of children. Ones that take ages to go down to sleep, and ones that don't sleep through the night..... but don't worry about that for atleast another 8 months 