The org.wildfly.bom
includes dependencies for the versions of Hibernate, RESTEasy, etc. as well as their dependencies that are used in WildFly. For if you use Jackson2 annotations the org.wildfly.bom:jboss-javaee-7.0-with-resteasy
should include the correct version of the Jackson2 dependency.
The org.jboss.spec
only include the Java EE 7 API's used.
If you're not using anything specific to WildFly then I would use the org.jboss.spec
BOM. If you're using something specific that the server includes, like Jackson2, Infinispan, etc., then I'd use the org.wildfly.bom
.