Attribute bonus points questions

[Mhaeric]

so since im pure dex on my bard if i switched to lancer it would have that dex bonus also?

If you put all DEX into Archer, then you will have all DEX on your Bard. It will not impact any of your other classes or jobs.
If you put all INT into Arcanist, then you will have all INT on your Summoner and your Scholar. It will not impact any of your other classes or jobs.

I.e. Every Class has 30 points to spend on that Class only. Other Classes do not benefit from points spent on other classes. Every Job uses whatever points you spent on its corresponding Class.