Horner's original soundtrack is just... perfect. While Tavera did a really good job with some of the later soundtracks but when you compare them to Whispering Winds, Great Migration or Discovery of the Great Valley... I cannot say there's really competition. The original LBT score is close to my favorite soundtrack, up there with Shore's LOTR music.

If We Hold on Together is a phenomenal song, summarizing the franchise's main themes into a three-minute, very thoughtful song. However, it's only one song and I'd say it's pretty artificial to separate it from the soundtrack. No offense.
Tavera has done many memorable, nostalgic songs like Night Flowers, the "Cavern theme" in JOTB and the musical version of If We Hold on Together . Many of them are able to define the films but the music when Littlefoot receives the tree star, when he chases his own shadow, the ending and nearly every other part of the first soundtrack is just so emotional, so great... IMO, you can't really compete with it.
And the sequel songs. While some of them could be worthy of the first film, some of them like Girls and Dads and Mad Song...
