Transmen have usually had mastectomies to get rid of the dreaded breasts.
Exactly so minus the breasts they do indeed have chests as do all men and all women.
Basically you feed a baby with breasts or bottle feeding. Bottle feeding is already a term we have and use with no problem, even the women who have breasts may also (or instead of) bottle feed.
The chest feeding bit is the bit I understand the least but all of it is utter nonsense.
"Will you be breastfeed or bottle feeding?"
Just pick one, you don't need to change any words or definition. If nothing else it's just making work for yourself.