Al Hanissim

My father shlita posted earlier this week that the Rambam understands קבעום ועשאום ימים טובים בהלל והודאה the הודאה is a reference to lighting the menorah.  He brings many sources in Rambam to support this idea.  The Riaz also understand the Gemorah this way.  However, Rashi understands that הודאה refers to the fact that we say al hanissim.  According to Rashi the establishment of Chanukah as a holiday is expressed in hallel and saying al hanissim.  This means that al hanissim is a way of mentioning the holiday like יעלה ויבא on Rosh Chodesh.  It is a mentioning of מעין המאורע just like יעלה ויבא (see Rashi Betzah 17a ד"ה בהודאה.)   However, the Rambam understands that it is a specific enactment to give thanks for the miracle but it is not a fulfillment of mentionning the holiday in prayer.  We can see this in the Rambam Laws of Tefillah (2:10,13)  בְּרָאשֵׁי חֳדָשִׁים וּבְחֻלּוֹ שֶׁל מוֹעֵד מִתְפַּלֵּל עַרְבִית שַׁחֲרִית וּמִנְחָה תְּשַׁע עֶשְׂרֵה בְּרָכוֹת כִּשְׁאָר הַיָּמִים וְאוֹמֵר בָּעֲבוֹדָה יַעֲלֶה וְיָבוֹא. בַּחֲנֻכָּה וּבְפוּרִים מוֹסִיפִין בְּהוֹדָאָה עַל הַנִּסִּים.  Why does he switch from אומר to מוסיף and why does he only say about יעלה ויבא that one prays תְּשַׁע עֶשְׂרֵה בְּרָכוֹת כִּשְׁאָר הַיָּמִים?  In light of how the Rambam learns we understand that the יעלה ויבא becomes part of the day's prayer, it is not a mere addition to the Shemonei Esrai, it transforms the Shemonei Esrai into a Rosh Chodesh Shemonei Esrai by mentioning מעין המאורע.  Al hanissim though does not make it a holiday prayer, it is just an addition to the prayer. That is why he only mentions the Shemonei Esrai with יעלה ויבא as being its own kind of Shemonei Esrai and about al hanissim he calls it just an addition.  (From a shiur of Rav Arial Ozar 5771.)