I trust not to thy phantom bliss,
The phantom that the speaker explicitly states she doesn’t trust is imagination. This ghost that haunts the speaker pushes her to the edges of society where she would feel the effects of loneliness that connect can only be soothed by hope that is birthed from death, as Steven Vine states in his essay about how the ghostly bliss “betrays the self’s desire” and is “born from the death that it is supposed to overcome” (107).
Thy world, where guile, and hate, and doubt, And cold suspicion never rise; Where thou, and I, and Liberty, Have undisputed sovereignty.
Our speaker is "othered" in these lines. She indicates how she is treated unfairly, but imagination allows her to live her life in peace. We can see how Brontë is reflected in this, a she is often referred to as "reclusive" and "solitary," contributing to the idea that she is more than likely part of the queer community. As Claire O'Callaghan states in her essay about Brontë, "Emily's reserve- ... does not correspond with typical gender norms and implies subversion."
And call a lovelier Life from Death.
The capitalization of "life" and "death" draws attention to how important the ideas are to the speaker. The very idea that life springs from death indicates how the world is viewed, and that the spirit of imagination gives more to our speaker, as she can imagine a better life. Steve Vine broadens this idea with imagination, "as if it would recover life's trophies from the tomb." https://www.jstor.org/stable/40003651