Hi, K.! For us, the bottle before bed was the last one to go. Our routine around 8 months was to give our daughter 3 small meals a day (at usual breakfast, lunch, & dinner times) to get her used to that, and we gave her a bottle in between breakfast & lunch and between lunch & dinner (at her nap times--9am & 1pm). Then, we also gave her a bottle at bedtime. Gradually, as she ate more table food at the meals, her appetite for the formula decreased, and she took less and less until eventually she didn't want the bottles during the day. Like I said, the bedtime bottle was the last to go, but it was probably phased out by 11 months. Pediatricians recommend formula/breastmilk for the first 12 months, so no need to rush her off the bottle until after that. Our daughter actually weaned herself--she just quit taking it!--around 11 months. She would turn her head away from it and refuse it, so it was easy for us. Take your cues from your baby. As long as she's at a healthy weight and you're offering her plenty of nutrients, she'll get what she needs. At 8 months, she most likely still gets a majority of her nutritional needs from formula/breastmilk.
So, to answer your specific question, I'd say to stop with that bedtime bottle around 12 months, give or take. Sounds like you have a good bedtime routine, so once the bottle is gone, just continue with what you've been doing and maybe add in storytime so you can still cuddle! Good luck!