I have a lot of experience in the banking domain. (Trust me.)
Generally LTV is understood as loan-to-value ratio, where value represents the estimate at origination of the loan of the property securing the credit. It's a credit risk metric, while RFM measures recency, frequency and monetary is shorthand for how much the customer spends. This leads to an assessment of how likely the customer is to seek credit from a lender.
Let's say a customer's M is to spend is to buy a house appraised at $1 million in period n, following by some other hypothesized sequence of purchases . To calculate LTV, you have to know what loan the lender is willing to make based on its underwriting criteria for the house, the car, the home improvement loan, the construction bridge loan, the HELOC, the second lien mortgage, the signature loan, ... and so on, and so forth.
That said, take a look at the rfm package, but I'd encourage you to clarify your algorithm.