If the Company A is giving three illustrative yields for the same portfolio for the same term (10 year) then it should follow that all such growths are for a certain present value

But it does not look so

Code:

Rate N FV PV
3.30% 10 £97,400.00 £70,397.26
5.12% 10 £117,000.00 £71,012.10
6.93% 10 £139,000.00 £71,124.48

If all you have in your portfolio is a collection of zero and coupon bearing bonds then a better way to evaluate the investment is to find the IRR or yield of the portfolio and then to find effective yield that you may compare with any of the offerings by Company A, B or any one else