It is possible to have a system with Intel(R) AMT configured to use an IP address that different than the host OS, though when using IPv4 addresses, both need to be setup to use static IP addresses. I'm not aware of any easy steps that can be taken to have the Intel(R) AMT platform configured to use a static IP address while the host OS is using DHCP, or if this is even supported.
However, since you are working with Intel(R) AMT version 6 systems, there is a new setting that allows the system to use DHCP to retrieve different IP addresses from the host OS if the network and DHCP/DNS servers are configured to support this. The setting is "Shared FQDN" and can be configured as "Enabled" or "Disabled". Basically, with this setting disabled -- not sharing the same FQDN as the host OS -- you would configure the FQDN of the Intel(R) AMT device differently than the host OS. This setting is available from the WebUI for the system and, I believe, from the MEBx configuration. Please note that when disabling this setting, you must also change the FQDN of the Intel(R) AMT device at the same time, otherwise the settings you attempt to apply will not be honored.
For example, assume your primary network domain is "vprodemo.com". In order to utilize this new setting, you would create a sub-domain called "me.vprodemo.com". Then, the Intel(R) AMT device would be configured to join the "me.vprodemo.com" domain while the host OS is configured for "vprodemo.com". Through some additional configuration steps for your DHCP/DNS servers you could have different ranges of IP addresses allocated for these domains.