It sounds like you're trying to create a sub-resource of an existing LWRP, so you're not "wrapping" it - you're "extending it". The LWRP syntax makes this less than desirable, because the resources are dynamically compiled into Ruby classes at runtime.
You could switch to HWRPs (the new Jenkins cookbook is a good example that uses inheritance and OO to extend resources and share attributes). By their nature, LWRPs are not very extensible, since they are dynamically rebuilt and reloaded at runtime.