When you bump a plugin's pom.xml, you must also bump its MANIFEST.MF (or feature.xml):
[ERROR] Failed to execute goal org.sonatype.tycho:maven-osgi-packaging-plugin:0.10.0:validate-version (default-validate-version) on project org.jboss.tools.bpel.tests.feature: Unqualified OSGi version 1.1.0.qualifier must match unqualified Maven version 1.1.1-SNAPSHOT for SNAPSHOT builds -> [Help 1]
If it's unclear what needs to be changed, run this script in some directory containing plugins/features:
http://anonsvn.jboss.org/repos/jbosstools/trunk/build/util/checkPOMvsManifest.sh