Yep, fine to steep in the bottles you're going to dispense from. Ready-mixes bought in shops / on-line are in the same type of bottles.
Many recipes do benefit from some time steeping - especially tobacco type flavors. Fruits and such may also benefit, but are usually good when mixed - although may improve with age.
Many recipes do benefit from some time steeping - especially tobacco type flavors. Fruits and such may also benefit, but are usually good when mixed - although may improve with age.