I spoke in IRC more about this.
In particular I was wrong to drag RBF into this, because it's a mempool thing, which I knew but simply forgot when making this post. I thought the best way to bring the topic up was to mention RBF since people are familiar with that concept and "bumping" a transaction.
Another user created this SE question:
http://bitcoin.stackexchange.com/questions/43003/is-there-a-way-to-create-a-transaction-that-it-can-only-be-confirmed-after-anothIt more clearly summarizes the question as:
Is there a way to create a transaction A that cannot be confirmed until B has been included in a block, although A does not build on any UTXO B creates?
To elaborate on this I think if Bitcoin had something that could do this we could make it very difficult to censor transactions individually. If someone had a tx being censored they could go onto social media and share that tx and others could begin "attaching" to the censored tx to promote it's processing as miners wouldn't get the fee of any txs attached to the censored one.