I was a member of the OEPFC of Great Britain many years ago but I got bored with all the politics between them and Sid Shaw's "Elvisly Yours" in London plus the addition of EPE's very own politics regarding the Fan Clubs and the use of Elvis' name. It kinda took all the light-hearted goodness of being an Elvis fan out of the equation.
Nevertheless, I presume now that if you were to book a trip to Memphis with the UK Fan Club that the person who is accompanying you would also be expected to become a club member - but, don't quote me on this.
I am only 'presuming' - a shocking thing to do, I know, but that is due to the recent promotion of "The Making of Elvis On Tour" DVD (I am just about to start a thread on this forum about this) and you have to be a member of the club to be in a position to place an order for this project which is to be released later this year.
I think it might be in your best interest to contact the club themselves about booking for Memphis - unless someone on the forum can help you with your query.