well-versed (?.)

• abreast of
• adept in
• at home in
• au courant
• briefed
• educated
• enlightened
• expert at
• good at
• handy at
• informed
• instructed
• master of
• posted
• primed
• proficient in
• schooled
• skilled in
• strong in
• taught
• trained
• up on
• up-to-date
• versed
• versed in
• well up on
• well-educated
• well-grounded
• well-informed
• well-posted
• well-read
• widely read