Per vsftp's config docs, have you tried:
If set to YES, local users will be (by default) placed in a chroot() jail in their home directory after login. Warning: This option has security implications, especially if the users have upload permission, or shell access. Only enable if you know what you are doing. Note that these security implications are not vsftpd specific. They apply to all FTP daemons which offer to put local users in chroot() jails.
If enabled, along with chroot_local_user , then a chroot() jail location may be specified on a per-user basis
. Each user's jail is derived from their home directory string in /etc/passwd. The occurrence of /./ in the home directory string denotes that the jail is at that particular location in the path.
Docs can be found at: