Well, there is a Maven Central repository but no p2 Central repository. When you specify a maven dependency, "it just works" because mvn has hard-coded logic that looks up this dependency at
repo2.maven.org, and everybody is interested in uploading their artifacts to maven central. In the case of p2 you have to specify p2 repositories where to look up the dependency.
The fact that you made p2 bundles available for dependency resolution via Help > Install new software suggests that you are not familiar with the Eclipse Target Platform concept. I think you should read up on it somewhere, e.g. at
http://www.vogella.com/tutorials/EclipseTargetPlatform/article.html In essence, a target platform is a transitive closure over all dependencies that you need. In maven you specify your external requirements via java import statements and pom.xml dependencies. In OSGi bundles (i.e. all Eclipse plugins) your specify your external requirements via MANIFEST.MF Require-Bundle and Import-Package statements. In maven the build tool looks up your external requirements at
repo2.maven.org and other explicitly specified repos. In Eclipse the PDE build looks up your external requirements in those p2 repos that you have explicitly specified. Tycho by default uses the same mechanism as PDE build, but with pom-first dependencies it will check
repo2.maven.org as well.
Bundle and plugin are essentially the same. The term bundle comes from OSGi world. In Eclipse bundles are used for plugins, which is an Eclipse concept. Before you ask, there is one more related term, p2 IU (installable unit), which is what p2 calls arbitrary jar files that may contain Eclipse features, plugins etc, and which can be installed via p2. I think sometimes folks mean a p2 IU when they say bundle.
As for your dependencies, you didn't specify which namespace they belong too. Are these java package names, Maven coordinates, Eclipse feature names, Eclipse plugin names, something else? Google search suggests that the first two are Eclipse plugins, whereas the third one seems to be a Maven artifact. You need to add Eclipse plugins to your target platform.