Is AES + RSA Encryption of individual log entries with the same key but different IVs secure?
Yes that would work; that's exactly what the IV is for. In this case the IV is really required to obtain confidentiality over multiple log entries. Note that public key operations are relatively fast for RSA (but nowhere near so fast as AES encryption, generally).

Mind though that there are many other possible leaks of information: size of ciphertext, time of logging, change of encrypted AES key (i.e. change of run). If those leak any info depends on you.

Also note that encryption by itself does not allow to detect change, duplication, removal etc. So you should make sure that this is acceptable to you as well. Signatures generation and sequence numbers can be part of a solution to create a cryptographically secured, auditable log file.