Short answer is yes. More complicated answer is as
@Rachox said. The general warning for trying a combination of breastmilk/formula (not including bottle confusion here) is that you need to the stimulation of breastfeeding/pumping for your body to produce enough milk in a supply/demand ratio, and if you supplement that with formula, your body is confused and thinks it doesn't need to produce as much as baby is feeding so it doesn't and then you have to use more formula for a hungry baby and then...your body thinks its milk is not needed.
I had a preemie who was in hospital for her first two months, so she had to be fed intravenously, then by bottle, though I was encouraged to pump breastmilk for her from the start, and they mixed it with formula for her bottle. I lived in the US at the time so had to go back to work after 12 weeks, and she went to daycare, where she was fed by breastmilk bottle/I pumped at work/breastfeeeding happened in evenings/nights/mornings. By Fridays though, my suppplies for daycare were a bit low and I couldn't provide enough for the afternoon feed, so daycare tried her on a bottle of formula and she refused it! So then they tried mixing breastmilk with formula, just like she'd had in hospital, and she refused it then too. Always.
So the point of my story is: whatever you do, be consistent with it - even a tiny baby gets used to what its supposed to be fed!