Difference between ca-bundle.crt and ca-bundle.trust.crt
ca-bundle.trust.crt
holds certs with "extended validation".
The difference between "normal" certs and certs with EV is that you EV certs need something like a personal or company validation by i.e. validating the identity of a person by his/her passport.
This means that if you want to get an EV cert you'll have to identify yourself to the cert issuer by i.e. your passport. If you "are" a company then an equivalent procedure (don't know it exactly) must happen. This is most essential for online banking: You must be sure that not only the server you connect to is certified but also the bank is certified.
Because of that the EV certs are more "complicated" and contain additional fields to "identify" not only the server but also the company.
To come back to your answer:
It depends on your usage. Most people should use ca-bundle.crt
. If you "are" a bank or an online shop which needs very high level of certification and "trust" then you should use ca-bundle.trust.crt
.