They can be the same partition, they are for different purposes though. EFI holds the EFI binaries as the name implies, while /boot holds the initrd, kernel, and the bootloader config files.
If they are the same partition, /boot needs to be formatted as FAT32 and have EFI as a subdirectory. Otherwise they can be separate partitions, either way the partition that contains the EFI directory needs to be formatted as FAT32.