Can my baby get RSV from someone who is on antibiotics for strep throat?

No. You are talking about 2 completely different diseases. Rsv (respiratory syncytial virus) is a respiratory virus which can cause bronchiolitis in babies. Strep throat is caused by a bacteria, group a strep. An antibiotic can treat a bacterial, but not a viral infection. However, both are contagious, so good hygiene is important to minimize spread.
Depends. If they have a cold at the same time they may be shedding RSV virus and pass it to anyone they contact. The strep throat is not a factor.

Related Questions

Within the last 7 weeks my 16 month old has had rsv, strep throat, constant green nasal drainage, & is now running temp of 103.2....Is this normal? Causes?

Reevaluation. No it is notnormal. The RSV virus may have lowered his resistence and consequently he develop other symptoms. Presumably, he has had green mucus more than ten days, in which case he should again be seen by the doctor to rule out a bacteril infection such as pnumonia. At the same time you might want to have his gamma globulins checked to make sure he isnt deficient. Read more...