Dear Naveen,
This is a best practice to have all the address families seperated and in your case its good to have address family IPV4 and activate the neighbors under it.
In future if you need a MDT IPV4 or IPV6 session to be established then we can do it easily if we have all the address families seperated. This is not only for the case of MPLS VPN, this can be for address family ipv6, mdt etc,..,.
The last point,,,,,, one neighbor relation ship and you can activate it in any of the address families you want, its easy right.
Hope you understood.
Please rate the post if it is informative.
Regards
Thanveer
"Everybody is genius. But if you judge a fish by its ability to climb a tree, it will live its whole life believing that it is a stupid."