Bartholomew Oobleck/Affiliation

Beacon Academy
Bartholomew is a professor at Beacon Academy.

Ruby Rose
Oobleck seems to have the utmost faith in Ruby's skills, praising her "genius intellect" in regards to bringing Zwei on their mission to the southeast quadrant as he considers dogs to be ideal companions for Huntsmen. After patrolling the area with her alone and observing a herd of Goliaths, Ruby asks him why he became a Huntsman.

Oobleck responds that he did so upon realizing that he could use tragedies such as those that befell Mountain Glenn in order to learn from past mistakes, thereby honoring those who were lost. He ends by stating that he chose this path because there is nothing else that he would rather be.

Additionally, Ruby is the only member of her team that he did not ask her reason for being a Huntress, but his reasons for this are unknown.

Jaune Arc
So far, Bartholomew has been hard on Jaune, who was first seen asleep in his class and subsequently revealed to be doing poorly in it since day one.

Bartholomew is disappointed in Jaune's incorrect answers and, believing him to lack interest in the course material, tries to impress upon him the importance of his history classes.

Cardin Winchester
Like Jaune, Cardin is also doing poorly in the history class, possibly due to his stubbornness, and has become the target of Bartholomew's negative attention. He was also held back after class to receive extra reading and essay material.

Bartholomew might have more of a dislike of Cardin than with Jaune as he was seen shaking his head in dismay at Cardin's cruel view of the Faunus warriors as mere animals.

Faunus
Bartholomew is very passionate about the mistreatment of those who have a Faunus lineage and seems to be almost enthusiastic about their victories over Humanity.

He harbors respect for Faunus and is utterly disappointed by the way others mistreat them, as seen in his reaction to Cardin referring to them as animals.

Peter Port
Oobleck is friends with fellow professor Peter Port. They are both seen having an amicable conversation during "Dance Dance Infiltration". Later in the volume, he is seen greeting Port with a friendly nod after Port and Team CFVY arrive at the scene on "Breach", before they both team up and fire at the invading Grimm. They later co-host the Vytal Festival combat tournament together. Peter also fondly refers to Oobleck by the nickname "Barty". When the Colosseum is attacked by Grimm, the two of them stay behind and fight together to ensure their students' safety and survival.

They also both stuck to Beacon for its repair and took a day off together to visit Taiyang at his home on Patch.

Taiyang Xiao Long
Oobleck is on friendly terms with Taiyang and visits him at his home on Patch with Professor Port when they both were in need of a break from the hard work of rebuilding Beacon while fighting off Grimm.

Zwei
Oobleck is pleased to see Zwei is brought on their mission, viewing dogs as reliable partners for Huntsmen. They appear to be in sync as Oobleck is able to perform combination attacks with Zwei soon after they meet. Zwei shows a fondness for Oobleck and sticks closely to him during RWBY's first mission, including during the battle with the Grimm in Vale.