If you analyze a vanilla tree with a Forestry treealyzer or Multifarm, they drop different saplings while remaining the same tree (the analyzed oak also drops five times the number of apples from its leaves on average). So you could technically have 8 different vanilla trees instead of just four... one analyzed and one non-analyzed version of each.
Jungle trees drop very few saplings though, making it barely even sustainable to replant them. If you want saplings for the bioreactor, I'd ignore them and just go with oaks, birches and spruce instead. That's already six different saplings with the analyzer trick.
And if you have a bee nearby, you can very quickly get mundane larch and silver lime trees bred out of those vanilla ones, giving you two extra types with little to no effort.