I had that problem this year too with a week and a half old bottle calf and I am an "expert" at bottle feeding
I had to deflate him like Silver said . You just use a 14/16 gauge needle and stick it in beside the umbilical cord while they are upside down and apply constant/smooth pressure on the balloon area until the air has been released . I also gave him bloat ease and mineral oil . Make sure you get some mineral oil down the calf , about a cup or so . Watch to make sure it is pooping and the poop is oily so you know that there is not a blockage which will be a much more serious matter altogether . Also, because you are poking a hole in them and they could be exposed to a bacterial infection I would also give a brood spectrum antibiotic JIC.
A week old calf should be getting 3 pints twice a day, so maybe you are mixing it too strong for them.
Good luck .