We do have the option to reward Diamonds to someone who made a previously unreproducible bug reproducible, but it is determined on a case-by-case basis, and it can't be offered on every bug (at least not at this point). Once an extra reward is made available, we will let you know in the topic the bug was reported in.
We're also continuously evaluating the reward process (it's new for us too, after all), so there may be some changes in the future. We tried to keep it as simple as possible, to make it clear to everyone how the system works. We do have to realise that Beta attracts players from literally every language version that Elvenar has to offer, and that not everyone may understand English perfectly. At this point we do like the results this reward system is giving us: a lot of people have taken up bug reporting, which helps us to improve Elvenar even more. But, if there are ways (that are also manageable for us) to improve the system further, we're of course open for that. We will certainly take your suggestions into consideration. This does not guarantee changes to the system, though - can't make promises there right now.