What's the ASN.1 structure of ECIES encryption result?
The public key structure is an X.509 SubjectPublicKeyInfo for ECC (public) key, using explicit format instead of (more common and popular) 'named' format. SPKI is a generic ASN.1 structure that supports multiple (and extensible) algorithms:

SEQUENCE {
    AlgorithmIdentifier = SEQUENCE {
        algorithm: OBJECT IDENTIFIER -- identifies the algorithm
        parameters: ASN.1 type and content varies depending on algorithm
    }
    publickey: BITSTRING -- content varies depending on algorithm
}


The algorithm-dependent parts for ECC are detailed in rfc3279 section 2.3.5 and yours has an explicit description of a curve over a prime field with 256-bit prime beginning 8542 in hex, coefficients beginning 7879 and 63e4, base point with X coordinate beginning 421d, and claimed order slightly less than the prime 
but cofactor 4 which doesn't make sense to me; and a public key/point on that curve with X coordinate beginning 0ae4.

SPKI is the format Java crypto calls 'X.509' (X509EncodedKeySpec) and OpenSSL calls PUBKEY.

The BouncyCastle IES output is created at the end of encryptBlock in the source here for org.bouncycastle.crypto.engines.IESEngine as the concatenation of 'V' the sender's ephemeral public key, 'C' the ciphertext, and 'T' the MAC tag, without any delimiters or other added structure. Your posted value is 91 bytes, beginning 04 meaning uncompressed, and for a 256-bit curve uncompressed V is 65 bytes, leaving 26 for ciphertext plus MAC, which seems unlikely; could your data be truncated or otherwise damaged?