Sim, é possível converter notas de rodapé em notas de fim, mas você não pode ter notas de fim e notas de rodapé no mesmo documento.
Na Ajuda do Pages '09:
Converting Footnotes to Endnotes and Vice Versa
In a word processing document, you can change all the footnotes in a document into endnotes, or all the endnotes into footnotes. You can also convert all document endnotes to section endnotes and vice versa. However, you can’t mix endnotes and footnotes in the same document.
To convert footnotes to endnotes and vice versa: In the Document pane of the Document inspector, change the setting in the Footnotes & Endnotes pop-up menu