They may choke and refuse the nipple again. Sometimes, after the baby realizes she's getting some nice, warm, familiar Mommy milk, she'll latch onto the bottle. Sometimes, after baby gets accustomed to taking milk from a source other than Mama's breast, she'll adapt to a bottle. Have the caregivers try a sippy cup, just dribbling small amounts of milk into baby's mouth. Be sure the caregivers are heating the milk enough but not too much.
Many babies are reluctant to take milk that is too hot or too cold.
Sometimes, when the baby can smell Mama, he'll take the bottle more readily. Have the caregiver hold the baby in the position you use while nursing. Often, the baby will associate that position with feeding and catch onto bottle-feeding. Holding the bottle near the caregiver's breast may help, but some folks are sort of squicked out by that idea for some odd reason. On the other hand, if the caregiver is already holding the baby in the position you normally use, have her try something slightly different.