I couldn't find studies analysing clearly enough tendons size, but a couple of sources show that they are probably correlated:
- One study found correlation between dimensions of Achilles'tendon and other ankle tendons (see table 2).
- Another study found correlation between height and dimensions of some tendons (see table 2).
Anyway, since correlation is not very strong, I doubt if the effect found is just the obvious correlation of dimension of all body parts to the general dimension of body - that is, bigger people tend to have bigger tendons, bigger bones, bigger livers, and so. It would be interesting to do a regression analysis of tendons dimensions taking in account body dimensions and other tendons dimensions. This way we could be able to see if people with some bigger tendon (compared with people of the same body size) tend to have other bigger tendons.