What happens to my pension if Vive goes bankrupt?

Your pension investments remain your property. They are held in your name at an independent custodian, separate from Vive's assets, and therefore fall outside the bankrupt estate.

Vive manages your portfolio but has no access to the money itself. In that case you can transfer your lijfrente account to another provider via the PSK, without fiscal consequences. The AFM supervises asset segregation.