I don't know where are you going, Madrid, Barcelona or Granada are the main cities I know with good companies and universities related to Bioinformatics. If you go to Barcelona there is an association Bioinformatics Barcelona which will be happy to help you. The main public institute of research is the Instituto Nacional de Bioinformática, which collaborate with many other public institutions like hospitals and universities, at the European level the main institution is the EMBL-EBI. You can find more people and groups of Bioinformatic through the RSG groups, they will known about the computational biology part, but maybe about personalized medicine too.
About the development and growth opportunities in Spain, I would say that many the companies are small, that is common in Europe, so you will probably be in a good position to develop yourself. Research groups in public institutions are completely different, usually in Spain they are quite rigid, and it is not easy for foreigners to promote, outside Spain they are more agile and it is easier to promote. The sector is growing, with more and more initiatives, both in Spain and all over Europe, specially related to health care.
About Personlized medicine: there is a big concern about online medical data, due to security and fiability. The initiative towards personalized medical care, at the moment are focused on individual test and fast accurate answers helping to decide what is better for the patient without using other external data.
I hope this helped.
PS: I would appreciate other views of Bioinformatics in Spain or in Europe too.
I think Jorge Amigo might be able to help you out.