I am a bit confused about where you are, where the pc with the phone and the vm is and where there sysadmins are.
I will also say that you make have better chance asking about this in the user forums of your VM (vmware? virtualbox? other?) . The fact is that if the CentOs does not show a /dev/ttyACM0 then its probably because one is not attached -virtually- to this VM. It is definitely NOT a gnokii error.
Having said that, I am using virtualbox for my VMs and in order for the USB device to be forwarded to the VM clients , one must -through the VM configuration manager - tell that they want the specific usb device should be forwarded to a specific client. Yo u can even automate that so that everytime the VM restarts the specific usb device will always be forwarded. If you're missing the /dev/ttyACM0 I strongly suggest you focus your investigation on the usb settings of the VM config manager. In Virtualbox : select client VM -> right click and goto settings -> select tab "usb" on the left panel -> add device (small icon with a blue plus sign).