This depends on your baby! Some babies are desperate to be fed immediately and you would not tolerate anything but feeding if they are hungry. Other babies are very spewy / refluxy and they might tend to vomit straight after a feed if placed on their tummy. The best thing to do would be to find what your baby likes best. Sometimes, in the first few months, using a pregnancy wedge or a pillow to create a soft incline helps minimise the spewing in tummy time (less pressure on your baby's tummy and a nice incline).