Am I less worthy to receive (and would not be able to receive at all) the great blessings of the tribe of Ephraim if I am pf other tribes?
First, the answer is “No, you are not less worthy” because you’re not of the tribe of Ephraim, any more than you’re less worthy simply because you’ve never been called as (for example) a relief society president or bishop. Many people never get called to certain positions. It doesn’t mean they are “less righteous” or “les worthy”. The Lord just wants you to perform a different role. That’s all. Nothing more. Nothing less.
Think of it in these terms. We all have different talents. And we are expected to do our best to fulfill our calling in life by making use of those talents. For some, we are asked to develop talents that we were not born with. And many do. Does the talent make one more or less worthy? No. If you have the mathematical abilities of an accountant or engineer, are you more worthy than the person who is a gifted musician or author who has trouble balancing his checkbook?
We are not defined by our talents. We’re defined by what we choose to do with those talents. And our worthiness is measured by how much we contribute to the world by using our individual talents.
For the present, we really have no distinction between any members of any tribes. We are all fellow Saints in the house of the Lord. We can all be called to any calling in the Church. We are all able to receive the same ordinances/covenants through the priesthood.
The reason we have a declared lineage in our patriarchal blessings will be made clear to us during the Millennium. During that period, we will be given different callings based on our House. But for now, it doesn’t really change much (with minor exceptions which usually amount to nothing).
See my previous post: Why Is it Important To Know That I’m From the Tribe of Ephraim?